# Adafruit PiCowbell Adalogger for Pico
## Overview
Ding dong! Hear that? It's the PiCowbell ringing, letting you know that the new **Adafruit PiCowbell Adalogger** is in stock and ready to assist your [Raspberry Pi Pico](https://www.adafruit.com/product/4864) and [Pico W](https://www.adafruit.com/product/5526) project with handy hardware and datalogging.
The PiCowbell Adalogger is the same size and shape as a Pico and is intended to socket underneath to make your next data logging or data reading project super easy. Micro SD card socket? Yes! STEMMA QT / Qwiic connector for fast I2C? Indeed. Real Time Clock with battery backup for accurate timekeeping? Of course!
**Please Note! There are a lot of possible configurations, and we stock various headers depending on how you want to solder and attach. Especially if you want the Pico on top so that the BOOTSEL button and LED are accessible.**
1. [Use the Pico Stacking Headers](https://www.adafruit.com/product/5582) if you want to be able to plug into a breadboard or other accessory with sockets.
2. [Use the Pico Socket Headers](https://www.adafruit.com/product/5583) if you want to plug directly in and have a nice solid connection that doesn't have any poking-out-bits.
3. [Use the Short Socket Headers](https://www.adafruit.com/product/5585) for a very slim but pluggable design; note that you'll want to trim down the Pico's headers or [use the short plug headers on the Pico](https://www.adafruit.com/product/5584) to have a skinny sandwich.
4. Solder the PCB directly to the Pico headers - of course, this is very compact and inexpensive, but you won't be able to remove the PiCowbell.
The PiCowbell Adalogger provides you with:
- **Right angle JST SH connector for I2C / Stemma QT / Qwiic** connection. Provides 3V, GND, IO4 (SDA), and IO5 (SCL).
- **MicroSD card holder** for adding as much storage as you could possibly want for reading or writing. Connected to SPI pins 16, 18, 19 and card select on 17. Optional card detect line can be connected to pin 15.
- **PCF8523 Real Time Clock with CR1220 Coin cell backup** for many years of timekeeping. Set the time once using our example sketches and then you can data-log with accurate timestamps. Uses I2C.
- **Reset button** - Press to restart your program.
- **Many pads on the Adalogger have a duplicate hole pad** next to it for solder-jumpering.
- **The ground pads have white silkscreen rectangles** to easily identify.
- Gold-plated pads for easy soldering.
If using the Philhower Arduino core, the Wire peripheral is already set up to use IO4 and IO5. If using CircuitPython or MicroPython, you'll need to let the code know to look at 4+5 for SDA+SCL pins.
**Does not come with a [micro SD card](https://www.adafruit.com/product/1294) or a [coin cell battery](http://www.adafruit.com/products/380). A CR1220 coin cell is required to use the RTC battery-backup capabilities!** We don't include one by default to make shipping easier for those abroad, [but we do stock them, so pick one up or use any CR1220 you have handy](https://www.adafruit.com/products/380).
# Adafruit PiCowbell Adalogger for Pico
## Pinouts
The default I2C address for the PCF8523 RTC module is **0x68.**
## Power
- **VB (VBUS) **- This is the micro-USB input voltage, connected to the micro-USB port on the Raspberry Pi Pico. It is nominally 5V.
- **VS (VSYS) **- This is the main system input voltage. It can range from 1.8V to 5.5V and is used to generate the 3.3V needed for the RP2040 and the GPIO pins.
- **EN (3V3\_EN) **- This connects to the enable pin on the Raspberry Pi Pico, and is pulled high (to VSYS) via a 100kΩ resistor.
- **3V ** - This is the 3.3V output from the Raspberry Pi Pico.
- **VR (ADC\_VREF)** - This is the ADC power supply and reference voltage. It is generated on the Raspberry Pi Pico by filtering the 3.3V supply. It can be used with an external reference when ADC performance is required.
- **G** - This is the common ground for power and logic. All **GND pins are highlighted in white on the silk** , with the exception of the ground pins on either side of the SD card slot. They are labeled **G.**
## I2C Logic
- **SCL** - I2C clock pin on the PiCowbell. It is connected to your microcontroller I2C clock line, which is **GPIO5** on the Pico. This connection is shared with the STEMMA QT port on the end of the board.
- **SDA** - I2C data pin on the PiCowbell. It is connected to your microcontroller I2C data line, which is **GPIO4** on the Pico. This connection is shared with the STEMMA QT port on the end of the board.
- [STEMMA QT](https://learn.adafruit.com/introducing-adafruit-stemma-qt) **-** These connectors allow you to connect to dev boards with STEMMA QT connectors or to other things with [various associated accessories](https://www.adafruit.com/category/619). There's one port at the end that connects to your microcontroller. The other four connectors in two rows of two are discussed below.
## Duplicate GPIO Hole Pads
The following pads on the PiCowbell Adalogger have a duplicate hole pad next to it for solder-jumpering:
- **GP0-GP11** , **GP20-GP22** , **Reset** , **A0-A2** , **VR** , **3V** , **EN** , **VS** and **VB**. Ground pins that have a duplicate hole pad are highlighted in white on the silk.
## microSD Card SPI
The microSD card slot is connected to the following pins for SPI:
- **MI** (MISO/GP16) - This is the SPI MISO ( **M** icrocontroller **I** n / **S** erial **O** ut) pin. It's used for the SD card to send data to the microcontroller.
- **SCK** (GP18) - This is the SPI clock input pin.
- **MO** (MOSI/GP19) - This is the SPI MOSI ( **M** icrocontroller **O** ut / **S** erial **I** n) pin. It is used to send data from the microcontroller to the SD card.
- **CS** (Chip Select/GP17) - This is the chip select pin for the SD card.
## SD Detect Jumper
On the back of the board, directly above **GP15** and to the left of the cowbell logo on the silk, is the SD Detect jumper. The jumper is labeled **SD Det** on the silk.
You can solder this jumper **closed** to connect the optional SD card detect line to **GP15**.
## Coin Cell Battery Holder
In the center of the PiCowbell is a holder for a CR1220 coin cell battery. Slot in a CR1220 battery into the holder to use the PCF8523 RTC battery-backup capabilities.
Warning:
### CR1220 12mm Diameter - 3V Lithium Coin Cell Battery
[CR1220 12mm Diameter - 3V Lithium Coin Cell Battery](https://www.adafruit.com/product/380)
These are the highest quality & capacity batteries, the same as shipped with the iCufflinks, iNecklace, Datalogging and GPS Shields, GPS HAT, etc. One battery per order (you'll want one battery per cufflink or pendant.)
Brand may vary but all battery brands are verified...
In Stock
[Buy Now](https://www.adafruit.com/product/380)
[Related Guides to the Product](https://learn.adafruit.com/products/380/guides)
## Reset Button
In the center of the board, to the left of the coin cell battery holder, is the reset button. It is labeled **RST** on the board silk. You can press it to restart your program.
# Adafruit PiCowbell Adalogger for Pico
## Assembly
Info:
There are four ways to get your PiCowbell board working with your Pico. To keep things flexible, PiCowbells do not come with headers: there's a lot of possible configurations and we stock various headers depending on how you want to solder and attach. Especially since you want the Pico on top, so that the BOOTSEL button and LED are accessible.
The options are as follows.
1. [Use the Pico Stacking Headers](https://www.adafruit.com/product/5582) if you want to be able to plug into a breadboard or other accessory with sockets.
2. [Use the Pico Socket Headers](https://www.adafruit.com/product/5583) if you want to plug directly into the Pico and have a nice solid connection that doesn't have any poking-out-bits.
3. For some PiCowbells: [Use the Short Socket Headers](https://www.adafruit.com/product/5585) for a very slim but pluggable design, note that you'll want to trim down the Pico's headers or [use the short plug headers on the Pico](https://www.adafruit.com/product/5584) to have a skinny sandwich.
4. For some PiCowbells: Solder the PiCowbell directly to the standard headers already soldered to your Pico. Of course this is very compact and inexpensive but you won't be able to remove the PiCowbell. However, this method is not possible for some PiCowbell variants depending on the clearance of the components on the PiCowbell (i.e. the PiCowbell Adalogger and its coin cell battery holder).
The next page shows how to solder standard headers onto a Pico board. The following four pages walk you through each type of PiCowbell assembly so you can choose the one that will work best for you!
Danger:
If you're unsure about soldering up the Pico and PiCowbell, check out our [FAQ on soldering](https://learn.adafruit.com/adafruit-guide-excellent-soldering/soldering-faq).
# Adafruit PiCowbell Adalogger for Pico
## Pico
Three out of four of the assembly methods included in this guide assume you have a Raspberry Pi Pico soldered up with standard male headers in preparation for using it with the PiCowbell Proto. This page will show you how to solder a set of standard headers to a Pico.
(The shorty header assembly method uses short male headers on the Pico. The soldering concept is exactly the same, but use the shorty male headers on the Pico instead of standard ones. You can follow these instructions with the shorty headers and you'll be set for that.)
Follow the steps below to solder the standard male headers to a Pico. The process is the same for all flavors of Pico, such as Pico W.
## Assembly Steps
Use the Pico to line up the headers on a breadboard. This is the easiest way to ensure the headers are soldered on straight.
Solder the pins on each end of the two header strips, so the four corners of the Pico are soldered. This ensures the Pico and headers are attached properly while you continue to solder the rest of the pins.
Solder the rest of the pins.
Remove it from the breadboard. You're done!
For a bit more detail on the process of soldering standard male headers to a board, check out [the How to Solder Headers' Male Headers page](https://learn.adafruit.com/how-to-solder-headers/male-headers).
# Adafruit PiCowbell Adalogger for Pico
## Stacking Headers
The first PiCowbell assembly method uses stacking headers, which allows you to use a breadboard with your PiCowbell-Pico sandwich. This is super helpful when you're still prototyping other parts of your project, or simply want jumper-wire access to the Pico pins in addition to the PiCowbell.
This page assumes you have already soldered standard male headers to your Pico. If you have not, please return to the [Pico assembly page](https://learn.adafruit.com/picowbell-proto/pico) and follow the steps there.
Follow the steps below to solder stacking headers to your PiCowbell.
Info:
## Assembly Steps
Place a standard-header-soldered Pico upside down on the table, so the long side of the header pins are facing up. Press the female sockets of each stacking header onto one of the rows of standard headers attached to the Pico, until they are fully attached.
**Ensure the PiCowbell is oriented correctly before beginning assembly. ** The PiCowbell should be top-down, so that you are looking at the bottom of the PiCowbell. **The STEMMA QT connector should be on the same end as the Pico USB connector, and the reset button should be on the opposite end with the Pico debug pins.**
The PiCowbell pins must match the pinout on the Pico.
Remember, the pins are labeled on the bottom of the Pico. In this case, that works well because they are labeled on both sides of the PiCowbell, allowing for direct comparison before attaching the PiCowbell to the stacking header assembly.
Warning:
Press the PiCowbell onto the male pins sticking up from the stacking headers. You may need to push the stacking header pins in or out a bit to get the PiCowbell attached.
With the stacking header male pins sticking up, the bottom of the PiCowbell should be facing up as well.
Solder the pins on each end of each stacking header, so that the opposite four corners of the PiCowbell are soldered on.
Solder the rest of the pins onto the PiCowbell.
You're done! Now you can attach the whole sandwich to a breadboard, have access to the pins via the breadboard, and still be able to use the PiCowbell as well.
# Adafruit PiCowbell Adalogger for Pico
## Socket Headers
This PiCowbell assembly method uses female socket headers on the PiCowbell to create a standalone sandwich when attached to a Pico with standard male headers.
This page assumes you have already soldered standard male headers to your Pico. If you have not, please return to the [Pico assembly page](https://learn.adafruit.com/picowbell-proto/pico) and follow the steps there.
Follow the steps below to solder socket headers to your PiCowbell.
Info:
## Assembly Steps
Place a standard-header-soldered Pico upside down on the table, so the long side of the header pins are facing up. Press the female sockets onto one of the rows of standard headers attached to the Pico, until both are fully attached.
**Ensure the PiCowbell is oriented correctly before beginning assembly. ** The PiCowbell should be top-down, so that you are looking at the bottom of the Cowbell. **The STEMMA QT connector should be on the same end as the Pico USB connector, and the reset button should be on the opposite end with the Pico debug pins.**
The PiCowbell pins must match the pinout on the Pico.
Remember, the pins are labeled on the bottom of the Pico. In this case, that works well because they are labeled on both sides of the PiCowbell, allowing for direct comparison before attaching the PiCowbell to the stacking header assembly.
Warning:
Press the PiCowbell onto the pins sticking up from the socket headers. You may need to push the stacking header pins in or out a bit to get the PiCowbell attached.
Solder the pins on each end of each socket header, so that the opposite four corners of the PiCowbell are soldered on.
Solder the rest of the pins onto the PiCowbell.
That's it, you're done!
# Adafruit PiCowbell Adalogger for Pico
## Shorty Socket Headers
This PiCowbell assembly method uses shorty female socket headers on the PiCowbell to create a standalone sandwich when attached to a Pico with shorty male headers.
This page assumes you have already soldered shorty male headers to your Pico. If you have not, please return to the [Pico assembly page](https://learn.adafruit.com/picowbell-proto/pico) and follow the steps there. The page shows how to solder standard male headers to the Pico, but the concept is identical with the shorty headers.
Follow the steps below to solder shorty socket headers to your PiCowbell.
Info:
## Assembly Steps
Solder the [short male headers](https://www.adafruit.com/product/5584) to the Pico. See the [Pico assembly page](https://learn.adafruit.com/picowbell-proto/pico) for instructions on soldering headers to the Pico.
Place a shorty-header-soldered Pico upside down (headers up) on the table. Press the each of the short female sockets onto one of the rows of short headers attached to the Pico, until both are fully attached.
**Ensure the PiCowbell is oriented correctly before beginning assembly. ** The PiCowbell should be top-down, so that you are looking at the bottom of the Cowbell. **The STEMMA QT connector should be on the same end as the Pico USB connector, and the reset button should be on the opposite end with the Pico debug pins.**
The PiCowbell pins must match the pinout on the Pico.
Remember, the pins are labeled on the bottom of the Pico. In this case, that works well because they are labeled on both sides of the PiCowbell, allowing for direct comparison before attaching the Cowbell to the stacking header assembly.
Warning:
Press the PiCowbell onto the pins sticking up from the shorty female headers. You may need to push the shorty header pins in or out a bit to get the PiCowbell attached.
Solder the pins on each end of each female header, so that the opposite four corners of the PiCowbell are soldered on.
**Try not to use too much solder on these four pins! The solder can wick into the associated female header socket, onto the inserted male pin, and permanently attach the two boards.**
Warning:
CAREFULLY remove the partially soldered PiCowbell from the Pico, before continuing to solder the rest of the PiCowbell pins.
As stated above, too much solder on the shorty female header pins can wick into the associated header socket, onto the inserted male pin, and permanently attach the two boards.
Solder the rest of the pins onto the PiCowbell. Be sure to keep the shorty female headers square while you solder the rest of the pins.
Press the PiCowbell onto the Pico to attach the two boards. Make sure you've oriented it correctly!
**The STEMMA QT connector should be on the same end as the Pico USB connector, and the reset button should be on the opposite end with the Pico debug pins.**
That's it! You're done!
# Adafruit PiCowbell Adalogger for Pico
## RTC with CircuitPython
Before using the real time clock (RTC) for the first time on the PiCowbell Adalogger, you need to calibrate it by setting the time with the **code.py** file below. After setting the time, the RTC module will use the coin cell battery to keep time even when you unplug the PiCowbell from the Raspberry Pi Pico.
Begin by inserting a CR1220 coin cell battery into the PiCowbell Adalogger battery holder. Then, attach the PiCowbell to a Pico or Pico W as described in the [assembly pages.](https://learn.adafruit.com/adafruit-picowbell-adalogger-for-pico/assembly)
### CR1220 12mm Diameter - 3V Lithium Coin Cell Battery
[CR1220 12mm Diameter - 3V Lithium Coin Cell Battery](https://www.adafruit.com/product/380)
These are the highest quality & capacity batteries, the same as shipped with the iCufflinks, iNecklace, Datalogging and GPS Shields, GPS HAT, etc. One battery per order (you'll want one battery per cufflink or pendant.)
Brand may vary but all battery brands are verified...
In Stock
[Buy Now](https://www.adafruit.com/product/380)
[Related Guides to the Product](https://learn.adafruit.com/products/380/guides)
Warning:
## CircuitPython Usage
To use with CircuitPython, you need to first install the [Adafruit\_CircuitPython\_PCF8523](https://github.com/adafruit/Adafruit_CircuitPython_PCF8523) module, and its dependencies, into the **lib** folder on your **CIRCUITPY** drive. Then you need to update **code.py** with the example script.
Thankfully, we can do this in one go. In the example below, click the **Download Project Bundle** button below to download the necessary libraries and the **code.py** file in a zip file. Extract the contents of the zip file.
Connect your Pico + PiCowbell sandwich to your computer via a known good USB data+power cable. Your board should show up as a thumb drive named **CIRCUITPY** in your File Explorer or Finder (depending on your operating system). Copy the **entire lib folder** and the **code.py** file to your **CIRCUITPY** drive.
Your **CIRCUITPY/lib** folder should contain the following folders and files:
- **/adafruit\_bus\_device**
- **/adafruit\_register**
- **adafruit\_pcf8523.mpy**
## Code
Once everything is saved to the **CIRCUITPY** drive, [connect to the serial console](https://learn.adafruit.com/welcome-to-circuitpython/kattni-connecting-to-the-serial-console) to see the data printed out!
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/PiCowbell_Adalogger_Examples/CircuitPython_Real_Time_Clock/code.py
## Setting the time
The first time you run the program, you'll need to **set the time**
find these lines:
```python
set_time = False
if set_time: # change to True if you want to write the time!
# year, mon, date, hour, min, sec, wday, yday, isdst
t = time.struct_time((2023, 3, 6, 11, 05, 00, 1, -1, -1))
# you must set year, mon, date, hour, min, sec and weekday
# yearday is not supported, isdst can be set but we don't do anything with it at this time
```
Change the `set_time` in the first line to be `True`:
`set_time = True`
and update the `time.struct_time` to have the current time starting from `year` to `weekday`. The last two entries can stay at -1
Re-run the sketch by saving and you'll see this out of the REPL:
Note the part where the program says it is `Setting time to:`
Now you can go back and change `set_time` to `False`:
`set_time = False`
and save, so you don't reset the RTC again.
The code will now output the time and date.
# Adafruit PiCowbell Adalogger for Pico
## RTC Python Docs
# Adafruit PiCowbell Adalogger for Pico
## CircuitPython Datalogging
Warning:
[Follow these steps to create the /sd directory](https://learn.adafruit.com/adafruit-memento-camera-board/circuitpython-memento-starter-projects)
The following example code will show you how use the PiCowbell Adalogger with CircuitPython to log data from a sensor to a file on an SD card with timestamps from the RTC module. In addition to a Raspberry Pi Pico and PiCowbell Adalogger, you will also need:
- CR1220 coin cell battery
- microSD card
- STEMMA QT cable
- MCP9808 Temperature Sensor
### CR1220 12mm Diameter - 3V Lithium Coin Cell Battery
[CR1220 12mm Diameter - 3V Lithium Coin Cell Battery](https://www.adafruit.com/product/380)
These are the highest quality & capacity batteries, the same as shipped with the iCufflinks, iNecklace, Datalogging and GPS Shields, GPS HAT, etc. One battery per order (you'll want one battery per cufflink or pendant.)
Brand may vary but all battery brands are verified...
In Stock
[Buy Now](https://www.adafruit.com/product/380)
[Related Guides to the Product](https://learn.adafruit.com/products/380/guides)
### SD/MicroSD Memory Card (8 GB SDHC)
[SD/MicroSD Memory Card (8 GB SDHC)](https://www.adafruit.com/product/1294)
Add mega-storage in a jiffy using this 8 GB class 4 micro-SD card. It comes with a SD adapter so you can use it with any of our shields or adapters. Preformatted to FAT so it works out of the box with our projects. Tested and works great with our
In Stock
[Buy Now](https://www.adafruit.com/product/1294)
[Related Guides to the Product](https://learn.adafruit.com/products/1294/guides)
### STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long
[STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long](https://www.adafruit.com/product/4399)
This 4-wire cable is 50mm / 1.9" long and fitted with JST SH female 4-pin connectors on both ends. Compared with the chunkier JST PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove.
Out of Stock
[Buy Now](https://www.adafruit.com/product/4399)
[Related Guides to the Product](https://learn.adafruit.com/products/4399/guides)
### Adafruit MCP9808 High Accuracy I2C Temperature Sensor Breakout
[Adafruit MCP9808 High Accuracy I2C Temperature Sensor Breakout](https://www.adafruit.com/product/5027)
The MCP9808 digital temperature sensor is one of the more accurate/precise we've ever seen, with a typical accuracy of ±0.25°C over the sensor's -40°C to +125°C range and precision of +0.0625°C. They work great with any microcontroller using standard I2C. With...
In Stock
[Buy Now](https://www.adafruit.com/product/5027)
[Related Guides to the Product](https://learn.adafruit.com/products/5027/guides)
Warning:
## CircuitPython Microcontroller Wiring
Connect the Raspberry Pi Pico and PiCowbell Adalogger as [described in the assembly pages](https://learn.adafruit.com/adafruit-picowbell-adalogger-for-pico/assembly). Next, insert a CR1220 battery into the coin cell battery holder on the PiCowbell Adalogger. Then, insert a microSD card into the PiCowbell Adalogger microSD card slot.
Finally, connect the MCP9808 STEMMA QT board to the PiCowbell Adalogger STEMMA QT port with a STEMMA QT cable.
## CircuitPython Usage
To use with CircuitPython, you need to first install the necessary libraries into the **lib** folder on your **CIRCUITPY** drive. Then you need to update **code.py** with the example script.
Thankfully, we can do this in one go. In the example below, click the **Download Project Bundle** button below to download the necessary libraries and the **code.py** file in a zip file. Extract the contents of the zip file, and copy the **entire lib folder** and the **code.py** file to your **CIRCUITPY** drive.
Your **CIRCUITPY/lib** folder should contain the following folders and file:
- **/adafruit\_bus\_device**
- **/adafruit\_register**
- **/adafruit\_pcf8523**
- **adafruit\_mcp9808.mpy**
## Example Code
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/PiCowbell_Adalogger_Examples/CircuitPython_Datalogger/code.py
Once everything is saved to the **CIRCUITPY** drive, [connect to the serial console](https://learn.adafruit.com/welcome-to-circuitpython/kattni-connecting-to-the-serial-console) to see status information from the code.
In the example, the microSD card is mounted and the file **temp.txt** is created to log temperature data from the MCP9808. Then in the loop, a temperature reading is taken and saved to **temp.txt,** along with the timestamp from the RTC module, every 30 seconds. Every time data is written to the file, `data written to the sd card` is written to the REPL to let you know that the code is running properly.
After logging data to the file, you can open **temp.txt** from the microSD card to see your data.
# Adafruit PiCowbell Adalogger for Pico
## RTC with Arduino
## Talking to the RTC
The RTC is an I2C device, which means it uses 2 wires to to communicate. These two wires are used to set the time and retrieve it.
For the RTC library, we'll be using a fork of JeeLab's excellent RTC library **,** [which is available on GitHub](https://github.com/adafruit/RTClib). You can do that by visiting the github repo and manually downloading or, easier go to the **Arduino Library Manager**
Type in **RTClib** - and find the one that is by **Adafruit** and click **Install**
Warning:
## First RTC test
The first thing we'll demonstrate is a test sketch that will read the time from the RTC once a second. We'll also show what happens if you remove the battery and replace it since that causes the RTC to halt. So to start, remove the battery from the holder while the PiCowbell is not powered or plugged into USB. Wait 3 seconds and then replace the battery. This resets the RTC chip. Now load up the matching sketch for your RTC
Open up **Examples-\>RTClib-\>pcf8523**
Upload it to your Pico connected to the PiCowbell Adalogger, as [described in the assembly pages in this guide](https://learn.adafruit.com/adafruit-picowbell-adalogger-for-pico/assembly).
Now open up the Serial Console and make sure the baud rate is set correctly at **57600 baud** you should see the following:
Whenever the RTC chip loses all power (including the backup battery) it will reset to an earlier date and report the time as 0:0:0 or similar. Whenever you set the time, this will kickstart the clock ticking.
So, basically, the upshot here is that you should never ever remove the battery once you've set the time. You shouldn't have to and the battery holder is very snug so unless the board is crushed, the battery won't 'fall out'
## Setting the time
With the same sketch loaded, uncomment the line that starts with **RTC.adjust** like so:
```
if (! rtc.initialized()) {
Serial.println("RTC is NOT running!");
// following line sets the RTC to the date & time this sketch was compiled
rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
```
This line is very cute, what it does is take the Date and Time according the computer you're using (right when you compile the code) and uses that to program the RTC. If your computer time is not set right you should fix that first. Then you must press the **Upload** button to compile and then immediately upload. If you compile and then upload later, the clock will be off by that amount of time.
Then open up the Serial monitor window to show that the time has been set
From now on, you won't have to ever set the time again: the battery will last 5 or more years
## Reading the time
Now that the RTC is merrily ticking away, we'll want to query it for the time. Let's look at the sketch again to see how this is done
```
void loop () {
DateTime now = rtc.now();
Serial.print(now.year(), DEC);
Serial.print('/');
Serial.print(now.month(), DEC);
Serial.print('/');
Serial.print(now.day(), DEC);
Serial.print(" (");
Serial.print(daysOfTheWeek[now.dayOfTheWeek()]);
Serial.print(") ");
Serial.print(now.hour(), DEC);
Serial.print(':');
Serial.print(now.minute(), DEC);
Serial.print(':');
Serial.print(now.second(), DEC);
Serial.println();
```
There's pretty much only one way to get the time using the RTClib, which is to call **now()**, a function that returns a DateTime object that describes the year, month, day, hour, minute and second when you called **now()**.
There are some RTC libraries that instead have you call something like **RTC.year()** and **RTC.hour()** to get the current year and hour. However, there's one problem where if you happen to ask for the minute right at **3:14:59** just before the next minute rolls over, and then the second right after the minute rolls over (so at **3:15:00** ) you'll see the time as **3:14:00** which is a minute off. If you did it the other way around you could get **3:15:59** - so one minute off in the other direction.
Because this is not an especially unlikely occurance - particularly if you're querying the time pretty often - we take a 'snapshot' of the time from the RTC all at once and then we can pull it apart into **day()** or **second()** as seen above. It's a tiny bit more effort but we think its worth it to avoid mistakes!
We can also get a 'timestamp' out of the DateTime object by calling **unixtime** which counts the number of seconds (not counting leapseconds) since midnight, January 1st 1970
```
Serial.print(" since 2000 = ");
Serial.print(now.unixtime());
Serial.print("s = ");
Serial.print(now.unixtime() / 86400L);
Serial.println("d");
```
Since there are 60\*60\*24 = 86400 seconds in a day, we can easily count days since then as well. This might be useful when you want to keep track of how much time has passed since the last query, making some math a lot easier (like checking if it's been 5 minutes later, just see if **unixtime()** has increased by 300, you don't have to worry about hour changes)
# Adafruit PiCowbell Adalogger for Pico
## Arduino RTC Docs
# Adafruit PiCowbell Adalogger for Pico
## Arduino Datalogging
The following example code will show you how use the PiCowbell Adalogger with Arduino to log data from a sensor to a file on an SD card with timestamps from the RTC module. In addition to a Raspberry Pi Pico and PiCowbell Adalogger, you will also need:
- CR1220 coin cell battery
- microSD card
- STEMMA QT cable
- MCP9808 Temperature Sensor
### CR1220 12mm Diameter - 3V Lithium Coin Cell Battery
[CR1220 12mm Diameter - 3V Lithium Coin Cell Battery](https://www.adafruit.com/product/380)
These are the highest quality & capacity batteries, the same as shipped with the iCufflinks, iNecklace, Datalogging and GPS Shields, GPS HAT, etc. One battery per order (you'll want one battery per cufflink or pendant.)
Brand may vary but all battery brands are verified...
In Stock
[Buy Now](https://www.adafruit.com/product/380)
[Related Guides to the Product](https://learn.adafruit.com/products/380/guides)
### SD/MicroSD Memory Card (8 GB SDHC)
[SD/MicroSD Memory Card (8 GB SDHC)](https://www.adafruit.com/product/1294)
Add mega-storage in a jiffy using this 8 GB class 4 micro-SD card. It comes with a SD adapter so you can use it with any of our shields or adapters. Preformatted to FAT so it works out of the box with our projects. Tested and works great with our
In Stock
[Buy Now](https://www.adafruit.com/product/1294)
[Related Guides to the Product](https://learn.adafruit.com/products/1294/guides)
### STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long
[STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long](https://www.adafruit.com/product/4399)
This 4-wire cable is 50mm / 1.9" long and fitted with JST SH female 4-pin connectors on both ends. Compared with the chunkier JST PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove.
Out of Stock
[Buy Now](https://www.adafruit.com/product/4399)
[Related Guides to the Product](https://learn.adafruit.com/products/4399/guides)
### Adafruit MCP9808 High Accuracy I2C Temperature Sensor Breakout
[Adafruit MCP9808 High Accuracy I2C Temperature Sensor Breakout](https://www.adafruit.com/product/5027)
The MCP9808 digital temperature sensor is one of the more accurate/precise we've ever seen, with a typical accuracy of ±0.25°C over the sensor's -40°C to +125°C range and precision of +0.0625°C. They work great with any microcontroller using standard I2C. With...
In Stock
[Buy Now](https://www.adafruit.com/product/5027)
[Related Guides to the Product](https://learn.adafruit.com/products/5027/guides)
Warning:
## Wiring
Connect the Raspberry Pi Pico and PiCowbell Adalogger as [described in the assembly pages](https://learn.adafruit.com/adafruit-picowbell-adalogger-for-pico/assembly). Next, insert a CR1220 battery into the coin cell battery holder on the PiCowbell Adalogger. Then, insert a microSD card into the PiCowbell Adalogger microSD card slot.
Finally, connect the MCP9808 STEMMA QT board to the PiCowbell Adalogger STEMMA QT port with a STEMMA QT cable.
## Library Installation
You can install the **Adafruit MCP9808** library for Arduino using the Library Manager in the Arduino IDE.
Click the **Manage Libraries ...** menu item, search for **Adafruit MCP9808** and select the **Adafruit MCP9808** library:
If asked about dependencies, click "Install all".
If the "Dependencies" window does not come up, then you already have the dependencies installed.
Warning:
## Example Code
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/PiCowbell_Adalogger_Examples/Arduino_PiCowbell_Adalogger_Example/Arduino_PiCowbell_Adalogger_Example.ino
Upload the sketch to your board and open up the Serial Monitor ( **Tools -\> Serial Monitor** ) at 115200 baud. You'll see the setup run with confirmation messages that the MCP9808 has been found over I2C and the microSD card has been initialized properly. As data is written to the microSD card, you'll see the message "`Writing to SD card`" appear in the Serial Monitor, along with the temperature reading and timestamp from the RTC. The onboard LED on the Raspberry Pi Pico will also light-up when a write is in progress.
After logging data to the file on the microSD card, you can open **datalog.txt** from the microSD card to see your data.
# Adafruit PiCowbell Adalogger for Pico
## Downloads
## Files
- [PCF8523 Datasheet](https://cdn-learn.adafruit.com/assets/assets/000/119/218/original/PCF8523.pdf?1678133979)
- [EagleCAD PCB files on GitHub](https://github.com/adafruit/Adafruit-PiCowbell-Adalogger-PCB)
- [3D models on GitHub](https://github.com/adafruit/Adafruit_CAD_Parts/tree/main/5703%20PiCowbell%20Adalogger)
- [Fritzing object in the Adafruit Fritzing Library](https://github.com/adafruit/Fritzing-Library/blob/master/parts/Adafruit%20PiCowbell%20Adalogger.fzpz)
## Schematic and Fab Print
## Primary Products
### Adafruit PiCowbell Adalogger for Pico - MicroSD, RTC & STEMMA QT
[Adafruit PiCowbell Adalogger for Pico - MicroSD, RTC & STEMMA QT](https://www.adafruit.com/product/5703)
Ding dong! Hear that? It's the PiCowbell ringing, letting you know that the new **Adafruit PiCowbell Adalogger** is in stock and ready to assist your [Raspberry Pi Pico](https://www.adafruit.com/product/4864) and
In Stock
[Buy Now](https://www.adafruit.com/product/5703)
[Related Guides to the Product](https://learn.adafruit.com/products/5703/guides)
## Featured Products
### STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long
[STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long](https://www.adafruit.com/product/4399)
This 4-wire cable is 50mm / 1.9" long and fitted with JST SH female 4-pin connectors on both ends. Compared with the chunkier JST PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove.
Out of Stock
[Buy Now](https://www.adafruit.com/product/4399)
[Related Guides to the Product](https://learn.adafruit.com/products/4399/guides)
### SD/MicroSD Memory Card (8 GB SDHC)
[SD/MicroSD Memory Card (8 GB SDHC)](https://www.adafruit.com/product/1294)
Add mega-storage in a jiffy using this 8 GB class 4 micro-SD card. It comes with a SD adapter so you can use it with any of our shields or adapters. Preformatted to FAT so it works out of the box with our projects. Tested and works great with our
In Stock
[Buy Now](https://www.adafruit.com/product/1294)
[Related Guides to the Product](https://learn.adafruit.com/products/1294/guides)
### CR1220 12mm Diameter - 3V Lithium Coin Cell Battery
[CR1220 12mm Diameter - 3V Lithium Coin Cell Battery](https://www.adafruit.com/product/380)
These are the highest quality & capacity batteries, the same as shipped with the iCufflinks, iNecklace, Datalogging and GPS Shields, GPS HAT, etc. One battery per order (you'll want one battery per cufflink or pendant.)
Brand may vary but all battery brands are verified...
In Stock
[Buy Now](https://www.adafruit.com/product/380)
[Related Guides to the Product](https://learn.adafruit.com/products/380/guides)
### Raspberry Pi Pico RP2040
[Raspberry Pi Pico RP2040](https://www.adafruit.com/product/4864)
The Raspberry Pi foundation changed single-board computing [when they released the Raspberry Pi computer](https://www.raspberrypi.org/archives/723), now they're ready to do the same for microcontrollers with the release of the brand new **Raspberry Pi Pico**. This...
In Stock
[Buy Now](https://www.adafruit.com/product/4864)
[Related Guides to the Product](https://learn.adafruit.com/products/4864/guides)
### Raspberry Pi Pico W
[Raspberry Pi Pico W](https://www.adafruit.com/product/5526)
The Raspberry Pi foundation changed single-board computing [when they released the Raspberry Pi computer](https://www.raspberrypi.org/archives/723), now they're ready to do the same for microcontrollers with the release of the brand new **Raspberry Pi Pico W**. This...
In Stock
[Buy Now](https://www.adafruit.com/product/5526)
[Related Guides to the Product](https://learn.adafruit.com/products/5526/guides)
### Adafruit MCP9808 High Accuracy I2C Temperature Sensor Breakout
[Adafruit MCP9808 High Accuracy I2C Temperature Sensor Breakout](https://www.adafruit.com/product/5027)
The MCP9808 digital temperature sensor is one of the more accurate/precise we've ever seen, with a typical accuracy of ±0.25°C over the sensor's -40°C to +125°C range and precision of +0.0625°C. They work great with any microcontroller using standard I2C. With...
In Stock
[Buy Now](https://www.adafruit.com/product/5027)
[Related Guides to the Product](https://learn.adafruit.com/products/5027/guides)
### USB cable - USB A to Micro-B
[USB cable - USB A to Micro-B](https://www.adafruit.com/product/592)
This here is your standard A to micro-B USB cable, for USB 1.1 or 2.0. Perfect for connecting a PC to your Metro, Feather, Raspberry Pi or other dev-board or microcontroller
Approximately 3 feet / 1 meter long
In Stock
[Buy Now](https://www.adafruit.com/product/592)
[Related Guides to the Product](https://learn.adafruit.com/products/592/guides)
## Related Guides
- [How to Add a New Sensor or Component to Adafruit IO WipperSnapper](https://learn.adafruit.com/how-to-add-a-new-component-to-adafruit-io-wippersnapper.md)
- [Adafruit Feather RP2040 with DVI Output Port](https://learn.adafruit.com/adafruit-feather-rp2040-dvi.md)
- [Adafruit QT Py ESP32 Pico](https://learn.adafruit.com/adafruit-qt-py-esp32-pico.md)
- [Plotting Offline Data - JSONL to CSV files, filters and graphs](https://learn.adafruit.com/plotting-offline-data-jsonl-to-csv-files-filters-and-graphs.md)
- [No-Code Offline Data Logger with WipperSnapper](https://learn.adafruit.com/no-code-offline-data-logging-with-wippersnapper.md)
- [Adafruit Trinkey QT2040](https://learn.adafruit.com/adafruit-trinkey-qt2040.md)
- [Adafruit QT Py ESP32-C3 WiFi Dev Board](https://learn.adafruit.com/adafruit-qt-py-esp32-c3-wifi-dev-board.md)
- [Adafruit MCP9808 Precision I2C Temperature Sensor Guide](https://learn.adafruit.com/adafruit-mcp9808-precision-i2c-temperature-sensor-guide.md)
- [NeoTrellis M4 Memory Game](https://learn.adafruit.com/neotrellis-m4-memory-game.md)
- [LIS3MDL Triple-axis Magnetometer](https://learn.adafruit.com/lis3mdl-triple-axis-magnetometer.md)
- [Adafruit 7-Segment LED FeatherWings](https://learn.adafruit.com/adafruit-7-segment-led-featherwings.md)
- [eInk Slow Movie Player](https://learn.adafruit.com/eink-slow-movie-player.md)
- [Adafruit CCS811 Air Quality Sensor](https://learn.adafruit.com/adafruit-ccs811-air-quality-sensor.md)
- [PyPortal Case](https://learn.adafruit.com/pyportal-case.md)
- [Matrix Portal Creature Eyes](https://learn.adafruit.com/matrix-portal-creature-eyes.md)