Reading channel B for HX711

[mr_byte31]

Hi All,

I make a small project. I use AVR to read load cell measurement using HX711.

I bought this board :

I read the datasheet but I couldn't get how to select/mulitplex between channel A or B for reading

datasheet : **broken link removed**

any idea?

 

[esp1]

hi 31,
The B channels is selected by sending 27 clock pulses during te data read sequence.
The Gain is fixed at 64.
E

 

[mr_byte31]

I read this part in the document but still doesn't make any sense.

when clock is started, the bits are present on the Dout. Till now the IC doesn't know how many clock triggers it will receive.

how would the IC put the results on the Dout without knowing how many clocks it will receive !!! this is very confusing !

 

[esp1]

hi mr,
My understanding is the Channel is selected after the first Read, so sending 26 clock pulses will select Channel 'B' at a gain of 32.
The next 26 pulses will output Channel 'B' data.
Normally I use 25 pulses in order to select 'A' at 128 and a Arduino lib for the HX.

Which library are you using for you HX711 program code.?

Note the misprint on the datasheet between Fig #2 and Table 1, Channel select for 27 pulses.


E

 

[mr_byte31]

what you said can be true but it is not in the datasheet
there is also another mistake on figure with pulses, they write channel B with different gains !

 

[FvM]

how would the IC put the results on the Dout without knowing how many clocks it will receive !!! this is very confusing !

what you said can be true but it is not in the datasheet
there is also another mistake on figure with pulses, they write channel B with different gains !

Seems like you didn't read the datasheet thoroughly. It's very clear about the number of clock pulses setting the parameters for the next conversion.

It's however unclear if 27 pulses select channel A (table 3) or B (figure 2). The first makes more sense.