I tried to power up my board with an external battery (not the x4 AA battery pack) because I need to feed an analog sensor too. The first trial the D9 diode break down! And I was worried 'cause board didn't turn on. Now I changed this diode and it turns on, connect to dongle and even I can program it too. But when I start streaming, all ADS signals seem to be railed or with a little noise, and no response to external biosignals; like if it doesn't exist reference or grounding.
I wonder if my ADS1299 could be damaged after diode burns? or how can I test if the ADS is correctly grounding or BIAS connected?
Jorch, can you clarify what type of external battery you connected to the board? What was the voltage? Some of the earlier 32 bit boards had a voltage regulator that could only handle (I think it was) 6 volts max. So for example if you had used a LiPo 2S cell (~8 volts) or a 9v alkaline battery, that could potentially have fried components such as the ADS1299. Later 32 bit boards were shipped with higher rated Vregs. The max voltage IS listed on the OpenBCI mainboard silk screen lettering.
See the "test signal" control commands below. They can turn on an internal test signal in the ADS1299.
Thanks for your response, @wjcroft. I'm using a 9V alkaline battery with a 5V regulator chip. My board has an operate voltage from 3-12 V that says in silk screen. I've been testing supply voltages from regulators, as following:
DVDD = 3.314 V OK
AVSS = 0.518 V X
AVDD = 2.499 V OK
I've already ask for a replacement of TPS72325 for -2.5V regulator. In the meanwhile, may I do the "test signal" response or first wait and change the regulator?
Well your -2.5 is clearly the issue. The test signals check some of the chip data paths, so may work even before you do that fix. In any event it looks like you have the solution. Sorry for this inconvenience.
HI, the 32 bit board also have a blue light indicating that is turn on? beacause the one that do not turn on the ligth when a swith to PC mode. I use the baterry pack with 4 AA batteries.
Yes I have, please tell me what to do, because I have test the voltaje of the batteries and all of them where around 1.6 V, thus, with the four of them I am above 6 V.
Hello, @biomurph, I changed the LM2664 voltage inverter and the problem was fixed. I didn't have to replace TPS72325. I´m working visualizing signals in Labview and everything looks normal. Thank you very much!!!
We have a problem where the board won't turn on. That is, it turns on for 1 second and then the LED switches off. Programming and flashing the board still works, but not in normal or BLE mode. Have measured D9 diode, and that is fine. Have also checked that AVDD and AVSS has +-2,5V and that is also fine. Do you know what can be the issue?
We need it working by wednesday so it is pretty time critical!
My problem was solved when I replaced the battery pack cable from another one! It seems that it was not well welded to the battery pack connectors ! check continuity just to be sure.
I have got the same issue. I replaced the diode D9, plugged in a 3.5V battery and got no response. Now when i check, the diode is again blown. Kindly help me figure out the issue.
I just unpacked my brand new 32-bit Cython board and powered it with the 4xAA battery pack but the LED doesn't make any light when I turn the board on. I'm also unable to get any data from it. So I took a multimeter and here is what I find : - there is 6.5V between the + and - terminals - I find 0.0V between the GND and DVDD, AVDD, or AVSS - D9 is working correctly - There is no continuity between AVSS and AGND
Do you know where the problem might come from and how to solve it ?
Very strange. All boards are tested before they leave. Was there an issue that occurred in shipping? Is this issue still persisting for anyone? I see this thread is getting a lot of traffic so I want to make sure there is not some bigger problem!
The LED not turning on is a big indicator of a problem booting the board.
Comments
Hello!
We have a problem where the board won't turn on. That is, it turns on for 1 second and then the LED switches off. Programming and flashing the board still works, but not in normal or BLE mode.
Have measured D9 diode, and that is fine. Have also checked that AVDD and AVSS has +-2,5V and that is also fine. Do you know what can be the issue?
We need it working by wednesday so it is pretty time critical!
Thanks in advance
I just unpacked my brand new 32-bit Cython board and powered it with the 4xAA battery pack but the LED doesn't make any light when I turn the board on. I'm also unable to get any data from it.
So I took a multimeter and here is what I find :
- there is 6.5V between the + and - terminals
- I find 0.0V between the GND and DVDD, AVDD, or AVSS
- D9 is working correctly
- There is no continuity between AVSS and AGND
Do you know where the problem might come from and how to solve it ?
Thanks in advance