The format of the HD-150 is different than that of the smaller scale. By default the scale is in WorldShip mode (a piece of UPS software). Its not a great format, and you need to press the Data button to have the transmisison occur. We suggest putting it into SCI.3 mode which is continuous data transmission with higher resolution. Check the manual in the download section for how to get it into that mode
You will then be able to read from the data stream at 9600 baud, 8N1 no flow control.
|:||W||' ' or '-'||lb1||lb2||lb3||'.'||lb5||lb6||l||b||S if stable||L if lowbatt||0x0D|
|:||W||' ' or '-'||kg1||kg2||kg3||'.'||kg5||kg6||k||g||S if stable||L if lowbatt||0x0D|
Basically, its ":W" followed by a space or minus sign, then 3 digits of whole lb/kg, a decimal point and two fractional digits. The data format scale is indicated by two characters, lb or kg' and then two status characters that will indicate if the reading has Stabilized and if the battery/power is Low
We don't have this scale with example code yet but you can probably adapt the python code above for the HD-150 or HD-300 without too much difficulty (and if you do please edit the wiki page to add it!)