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Topic: ESP-07S prototype miswiring, how to solve... (Read 193 times) previous topic - next topic

BosseB

I have had two prototypes built of a WiFi / serial converter project where I am trying to replace an obsolete WiFi module with an ESP-07S. The old board has been used minus the WiFi module (which was pluggable).
Both prototypes fail to start with the AiThinker AT-firmware and I have scratched my head to figure out what is wrong.
Turns out that I now discovered it:
Pin #3 (Enable) has been wired to GND instead of to 3.3V power!
Now my problem is that this wire runs beneath the module, which is glued to the board with RTV...
I might be able to reach the edge of the module enough to heat the solder and push the wire away.

Question:
Is it possible to start an ESP-07S with pin #3 (EN) floating or must it be tied to Vcc?
If I try to solder another wire to the pin (to supply +3V3 to it) I might accidentally reconnect the inaccessible wire beneath the module and make things worse (shortcircuit power).
So I would like to know if a floating EN pin is allowed?

Zapro

Why not cut the wire and move the loose end to +3.3V?

// Per.

BosseB

Because it is soldered to the edge pad #3 on the underside of the module and the module itself is glued to the board with RTV, which I cannot pry away without destroying the board and module. There is a 1.5 mm space between the board and the module (the thickness of the glue blob) and this wire is inside the glue, I believe...

But I managed to heat the pad and with a needle I could dislodge the wire and push it inside the space.
Then I soldered another wire between pins 3 and 8 and tested again.
This time the module seems to have started because now there appears an Access Point with an SSID starting with AI-THINKER...
But something else is wrong still because the serial line does not work, no response to AT commands at 115400 baud...
Need to check the wiring of the TxD and RxD lines through the TTL-RS232 level shifter.


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