Reply To: Please Help! Meter CTD Gen2 being blocked by Yosemitech 511-a

We have two stations that developed the same problem in August of 2023. One station is here: 

We have two stations that developed the same problem in August of 2023. One station is here:  https://monitormywatershed.org/sites/GVWA%20107/

Both were V1.0 Mayfly with the LTE Bee, Hydros21 CTD and Yosemitech 511-a Turbidity sensors with the Modbus-Mafly-Wingshield .  The Hydros21 is using the new 500 and 1000 ms timings and the voltage jumper is set to 3.3 volts.  The wingshield is getting 5 volts switched from the header (pin 11) and using the U3V12F9 boost regulator.

First symptoms in August were the CTD returning -9999 and -9991, which are bad measurement and low voltage error codes.

We replaced the V1.0 boards with V1.1 rev B boards this week but the problems persists.   However, disconnecting one or the other of the sensors results in normal operation for the connected sensor.  Is it likely that there is insufficient power getting to the sensors during sensor operation? If so, could I try:

• getting 12 volt for the 511-a from pin 9 on the header (now that the 12 volt boost has been upgraded) and removing the U3V12F9?
• the above, but also altering SJ25 to get 9 volts?
• change SJ27 and monitor for voltage sag?

It is always possible to run a jumper from the LIPO header to a second board as a workaround.

Thanks for any insights,

Mike