4 Replies Latest reply on Aug 19, 2018 7:06 PM by rzzh

    Deep sleep current draw issues with SWD pins and debugger

    rp_2857406

      I have a custom board using a CYBLE-212019-00 PRoC module connected to a couple of sensors using SPI and transmitting over BLE. The board is connected through a custom cable to the CY8CKIT-042-BLE for programming and debugging (pins 0.6 and 0.7 for SWD, Xres, 3.3V, and ground are connected.) The hardware all works for programming and debugging; next step was to try deep sleep mode.

      After some work, and using code similar to AN92584 on BLE, I can get it to go to deep sleep while connected to the debugger. BLE works. Average current with SPI and ADC shut down is about 1.8 mA in debug mode. Allowing for about 1.5 mA for debugger (from other sources) this says I am drawing a few hundred uA, which is okay for now.

      Problem is, when I try to disconnect the debugger (set the serial wire debugger pins to GPIO), instead of the current dropping, it increases and fluctuates in the 6 to 10 mA range.

      I have tried programming in Release mode, and powering my board completely separately with just 3.3V to the board. Still same fluctuating high current.

      Do Xres or the SWD pins need to be pulled to a certain level?

       

      I am using PSoC Creator 4.1 Update 1.

       

      Thanks for any suggestions.

       

      Randy