Hello everyone,
I'm working on some project and I want to establish SPI communication between ADS1198 and AM1808 microcontroller. When I send "START" command (0x08) from my application to ADS1198 then conversion starts. After that, I am sending "RDATAC" (Read Data Continuous Mode - 0x10). My AM1808 receiving 19 bytes from ADS1198 in the following format: 24 status bits + 16 bits for 8th channel + 16 bits for 7th channel + 16 bits for 6th channel + 16 bits for 5th channel + 16 bits for 4th channel + 16 bits for 3rd channel + 16 bits for 2nd channel + 16 bits for 1st channel = 152 bits (19 bytes).
On my terminal I'm getting following 19 bytes:
192 255 255 255 255 0 0 0 0 0 0 0 0 0 0 0 0 0 0 (first 3 bytes = 1100 0000 1111 1111 1111 1111)
192 255 255 255 255 0 0 0 0 0 0 0 0 0 192 255 255 255 255
192 0 223 223 223 223 0 0 0 0 0 0 0 0 0 0 0 0 0 (1100 0000 0000 0000 1101 1111) - in this case channel 2 is ON
192 255 255 255 255 0 0 0 63 191 191 191 128 0 0 0 0 0 0
192 255 255 255 255 0 0 0 0 0 0 15 239 239 239 224 0 0 0
..........
First 3 bytes are status bits (1100 + LOFF_STATP (8 bits) + LOFF_STATN (8 bits) + bits[4:7] of the GPIO register). As you can see, I'm getting "192" (1100 0000) and first 4 bits are OK, according to datasheet. Next 16 bits stores the status of whether the positive or negative electrode on each channel is on or off ('0' is lead-on (default) and '1' is lead-off). Based on the received data I'm concluding that channels all channels are OFF (LOFF_STATP = 0000 1111 and LOFF_STATN = 1111 1111 or in other case LOFF_STATP = 0000 0000 and LOFF_STATN = 0000 1101). Considering received data I'm getting something on the different channels.
My question is: Is this received data OK? I was searching for the answer through the datasheet but I didn't find.
Best regards,
Vladimir