ESP32 Forum

I have an esp32 devkitc connected to an USB to ttl FTDI mounted on a bread board.

The esp32 also connects to an OLED and an RGB LED

I am able to connect to the network, light up the LED and write to the OLED.

I can also see the console using Thonny IDE.

I am wanting to test the esp32 running on a breadboard power supply (I was unsure if the USB cable was sending proper voltage consistently and wanted to see if I can have it run for a few days or so ), so I simply pulled the power and ground away from the FTDI and moved them onto the breadboard power supply.

However, I can no longer get OLED output or see any output in Thonny (my pc can see the USB/FTDI).

Is my problem clear? I don't have a great way of easily describing of of the connections, but here's a pic:

https://postimg.cc/ftsxkd3n

Would it be possible to power the esp32 breadboard power supply as well connect to and see the REPL?

I'd really like to debug and upload code whilst it is powered via breadboard power supply?

Could you make sure power supply of FTDI board is enough? As you know, supply current is required to be at least 500 mA for ESP module.

Are the grounds on the two supplies connected? Without connecting the breadboard and USB grounds, they have no common frame of reference.

Craige Hales wrote: ↑

Thu Oct 13, 2022 10:24 am

Are the grounds on the two supplies connected? Without connecting the breadboard and USB grounds, they have no common frame of reference.

Hi Craige. They were %100 not connected. I was trying to keep them separate to 'convince' myself that I was supplying power to the esp32 via the BB power supply. And I was thinking not to use jump wires for the FTDI, mainly b/c it could be powered by USB.
(just started my journey into electronics and am learning via courses and such, but still fumbling along...)

I did connect the ground via jumpers. That did not quite seem to make it work though. I'll continue tshooting...

ESP_LJH wrote: ↑

Thu Oct 13, 2022 7:03 am

Could you make sure power supply of FTDI board is enough? As you know, supply current is required to be at least 500 mA for ESP module.

Thanks. So it looks like for this board, in 5V mode the maximum current draw on this pin is approximately 500 mA.

On checking it seems like I was getting 20 ma from the FTDI to the esp32.

Craige Hales wrote: ↑

Thu Oct 13, 2022 10:24 am

Are the grounds on the two supplies connected? Without connecting the breadboard and USB grounds, they have no common frame of reference.

Thanks Craig. I replied but I don't see my post yet. I am reposting now.

In short, they were not connected. I was thinking they did not have to be (I then researched the topic - I guess newer ppl don't know that!)

I then connected them:

The esp32 and oled share a ground as well as the esp32 and FTDI now do as well.

https://postimg.cc/5Hk3y2nM <=== Here's a new picture. I really hope it is helpful.

The esp32 and oled are being powered by either sides of the BB power supply. I can write 'hi' to the oled and get output in Thonny but I do see "Brownout detector was triggered" now.

ESP_LJH suggested to check power. The FTDI PDF says 'in 5V mode the maximum current draw on this pin is approximately
500mA" but I am not using the VCC at all. I checked either sides of the BB power supply - both are getting 4.92 V.

I checked the current at the FTDI, but don't think I did correctly.

What sort of supply are you using with the red board? I can't tell if there is a wall-wart connected to the connector at the top right. That supply should be >= 700 ma, preferably a 7 to 9V, >= 1A supply (I read that 12V makes the red board run hot.) The red board is probably like most of them and rated for only 700 ma. (I just recently bought my first, so my experience is a bit limited...)
A typical USB cable will not supply enough current when the ESP32 WIFI is transmitting; 700 ma seems to be enough.
If you are watching the log to see the brownout message, you might also be able to add some more printf to see what you are doing that triggers the brownout.

Craige Hales wrote: ↑

Fri Oct 14, 2022 3:20 pm

What sort of supply are you using with the red board? I can't tell if there is a wall-wart connected to the connector at the top right. That supply should be >= 700 ma, preferably a 7 to 9V, >= 1A supply (I read that 12V makes the red board run hot.) The red board is probably like most of them and rated for only 700 ma. (I just recently bought my first, so my experience is a bit limited...)
A typical USB cable will not supply enough current when the ESP32 WIFI is transmitting; 700 ma seems to be enough.
If you are watching the log to see the brownout message, you might also be able to add some more printf to see what you are doing that triggers the brownout.

Right ... It is a 5V 250 ma wall wart adapter. Oh dear. It seems like I need more amps! And Volts.

To be honest, I don't really know (obviously) how to proper plan for power on circuits with micro-controllers and such..

Not coming from an EE background, I just assumed a 5V supply would be good as most of the interwebs toss it about.

Yes, good point on the print statements as well.

Will try a new adapter as soon as I can locate a good candidate - Thanks!!

Will try a new adapter as soon as I can locate a good candidate - Thanks!!

I tried a 12 V / 1 amp. It did not make it all work. That's OK. The reason I was doing this was because I thought there were power issues but seems like I am making worse.

FWIW, I put in all back simply using a USB cable as power - for the oled as well as the RGB LED.

My little voltmeter says it's getting 30-50 MA (it's a $5 usb thing).

I do not get brown outs (at least not yet and when I did they usually came fast).

At some point I intend to get this on a pcb...

I will try to go for it again as my original post said but really but I suppose I need to learn a lot more

Many thanks to all the respondents!