Hello! I am getting odd samples from TSC_ADC, definitely I am missing something. Can you help me to figure out what I am missing, please?
I am using a beagle bone black industrial by element14, debian 8.6, code composer studio v7, and this header <https://github.com/lore4/TSCADCss/blob/master/sys_tscadcss.h>. Sampling is done in this <https://hastebin.com/rucoludive.cs> code, which send data to an ARM task counterpart which displays values on stdout. The aim is to understand how to sample via TSC_ADC. :) Currently, I am sampling a channel (i.e. inp = AIN6 = 1.6V, double checked with multimeter and oscilloscope) via TSC_ADC. This channel is sampled in single-ended mode and in differential mode (i.e. inm = AIN0 = GND ADC ). In order to do that, I am using 2 steps of TSC_ADC (i.e. from STEP1 and STEP2): the first step has differential mode enabled (i.e. STEP1 ), while the other step has single-ended mode enabled (i.e. STEP2). All steps averaging is set to 4 (i.e. 16 samples). The resulting samples expressed as decimals are about: - 1600 from STEP1; - 1950 from STEP2. These samples should be converted as 1.6V, but they do not by using official "formula" <http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver's_Guide#Formula_Used_for_Calculation>. For example, 1.6 / 4095 * 1.8 = 3640. What I am doing wrong? : \ In order to enable the sampling, the following setps are done in such order in this <https://hastebin.com/rucoludive.cs> code: CTRL register is set to 6, STEP1 & STEP2 Averaging is set to 4, STEP 1 Diff_CNTRL is set to 1, STEP1 & STEP2 SEL_INP_SWC_3_0 is set to 6, STEP1 SEL_INM_SWC_3_0 is set to 0, STEPENABLE register is set to 6, and CTRL register is set to 7. Best regards, Lorenzo -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/18c64141-de14-4553-b0de-1726b5e4c995%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
