Linux/ADS1299: The value of the CH1 data is different

Keunsoo Shin

Prodigy 75 points

Part Number: ADS1299

Tool/software: Linux

I develope ADS1299 on raspberry zero w

first I set board option Bipolar and input 2.8 v on channel 1.

and run rdatac mode

but I get 467xxx value on ch1 data

Is there anything I missed on datasheet?

my config option and ch set =

config1 : 96

config2 : c0

config3 : e0

ch1 set : 00

over 5 years ago

0 Alexander Smith over 5 years ago

TI__Mastermind 47625 points

Hi Keunsoo,

Thanks for your post!

Can you provide additional information?

This post covers code to voltage conversion:e2e.ti.com/.../1363393, however I need to know what your reference voltage is in order to calculate the LSB.

0 Keunsoo Shin over 5 years ago in reply to Alexander Smith

Prodigy 75 points

my board set is bipolar and ch set 0000 0000
ch1 is composed of 10k resistance and 50variable resistance.
so max input 2.8v
but Iexpected ch1 max data 28xxxx but I get max ch1 data 467xxx
Is there anything I missed on datasheet?

0 Alexander Smith over 5 years ago in reply to Keunsoo Shin

TI__Mastermind 47625 points

Keunsoo,

Are you converting the code to voltage correctly as I indicated in the previous post?

0 Keunsoo Shin over 5 years ago in reply to Alexander Smith

Prodigy 75 points

OK I read your previous post and apply my source code

I compared Volt with data

but some difference between V and data

Below is a table of the information.

V data

2.774	2.756	-0.018
2.583	2.726	0.143
2.509	2.641	0.132
2.391	2.506	0.115
2.241	2.358	0.117
2.167	2.283	0.116
2.004	2.114	0.11
1.855	1.967	0.112
1.789	1.881	0.092
1.658	1.748	0.09
1.557	1.634	0.077
1.444	1.522	0.078
1.355	1.422	0.067
1.254	1.321	0.067
1.147	1.201	0.054
1.052	1.101	0.049
0.918	0.969	0.051
0.811	0.856	0.045
0.698	0.734	0.036
0.491	0.514	0.023
0.381	0.401	0.02
0.178	0.188	0.01

0 Alexander Smith over 5 years ago in reply to Keunsoo Shin

TI__Mastermind 47625 points

Keunsoo,

This variation is probably caused by noise in the system.

Data converters

Data converters forum

Linux/ADS1299: The value of the CH1 data is different