I have an HC-05 wired with an Uno, and am using a sketch to control the HC-05 AT mode and send AT commands, per a variant of this instructable: DIY Arduino Bluetooth Programming Shield

The error I have is simple in appearance, when AT mode is signaled off by bringing HC-05 pin 34 low after being high, then a low pulse is sent from the HC-05 to the HC-05 pin 32 which is wired to the Uno reset pin per the instructable. The low pulse should not be occurring and is triggering the Uno to reset, even though it is only 1-2ms. The low pulse also occurs when the HC-05 is powered on, neither low pulse occurs if the polar command is reset to normal "1,0".

After receiving the "AT+POLAR=1,1" command the HC-05 pin 32 should trigger low when a BT connection is made to the HC-05, that part works correctly. The other low pulses triggering the Uno to reset when signaling to leave AT mode and when powering on the HC-05 are causing problems with running the sketch so I need to determine how to stop them. I have checked the AT settings I am familiar with and they are as expected.

Any ideas are appreciated. Thanks for your help.


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