1. From 0,625 to 1.25 OK. < 0.625 V allways 2048 ?!?
2. can't calibrate gain to 4096 mostly to 4079....4081
SINGLECTRLX - VREFSEL = 2
VREFATTFIX = 0
VREFFATT = 8
VINATT = 14
DVL = 0
FIFOOFACT = 1
PRSMODE = 0
PRSSEL = 0
SINGLECTRL - REP = 0
DIFF = 0
ADJ = 0
RES = 3
REF = 7
POSSEL = 0x87
NEGSEL = 0xFF
AT = 5
PRSEN = 0
CMPEN = 0
CTRL - WARMUPMODE = 3
SINGLEEDWAWU = 0
SCANDMAWO = 0
TAILGATE = 0
ASYNCCLKEN = 0
ADCCLKMODE = 0
PRESC = 0
TMEBASE = 5
OVSRSEL = 6
CHCONMODE = 0
Anybody any idea ?
Thanks
arnold
Discussion Forums
32-bit MCUs
Unanswered
Hi Arnold,
We have found this problem can occur when the ADC SAR clock exceeds its maximum specified frequency of 16MHz. Since you have the prescaler set to 0 (divide by 1), depending on which oscillator you are using, you may be running the ADC out of spec. Try changing the prescaler value and see if that addresses the problem. Let me know if you have any questions.
Regards,
Joe
0
Why was this topic (re)moved? It contains valuable information for anyone experiencing the same problem.
0
Hi vanmierlo,
We agree that this thread should be in the 32-bit forum, so we're looking into why this was moved.
~Tabi
0
This thread was originally deemed a duplicate, but since both now have replies, I've added this back to the 32-bit forum. The duplicate thread is here:
I found that slowing the clock fixed my problem which was finding that the ADC stopped working when the supply voltage dropped below 2.4V. With the slower clock it works fine all the way down to 1.8V
Strange behave of results of EFR32 / BGM113
I have a strange result from the ADC:
Help wellcome.
Vref = EXT 1.25 V
SINGLEOFFSET = 0x8
SINGLEOFFSETINV = 0xA
SINGLEGAIN = 0x00
Problems:
1. From 0,625 to 1.25 OK. < 0.625 V allways 2048 ?!?
2. can't calibrate gain to 4096 mostly to 4079....4081
SINGLECTRLX - VREFSEL = 2
VREFATTFIX = 0
VREFFATT = 8
VINATT = 14
DVL = 0
FIFOOFACT = 1
PRSMODE = 0
PRSSEL = 0
SINGLECTRL - REP = 0
DIFF = 0
ADJ = 0
RES = 3
REF = 7
POSSEL = 0x87
NEGSEL = 0xFF
AT = 5
PRSEN = 0
CMPEN = 0
CTRL - WARMUPMODE = 3
SINGLEEDWAWU = 0
SCANDMAWO = 0
TAILGATE = 0
ASYNCCLKEN = 0
ADCCLKMODE = 0
PRESC = 0
TMEBASE = 5
OVSRSEL = 6
CHCONMODE = 0
Anybody any idea ?
Thanks
arnold
Hi Arnold,
We have found this problem can occur when the ADC SAR clock exceeds its maximum specified frequency of 16MHz. Since you have the prescaler set to 0 (divide by 1), depending on which oscillator you are using, you may be running the ADC out of spec. Try changing the prescaler value and see if that addresses the problem. Let me know if you have any questions.
Regards,
Joe
Why was this topic (re)moved? It contains valuable information for anyone experiencing the same problem.
Hi vanmierlo,
We agree that this thread should be in the 32-bit forum, so we're looking into why this was moved.
~Tabi
This thread was originally deemed a duplicate, but since both now have replies, I've added this back to the 32-bit forum. The duplicate thread is here:
http://community.silabs.com/t5/Bluetooth-Wi-Fi/Strange-behave-of-results-BGM113/m-p/193341/highlight/true#M18640
~Tabi