Search found 38 matches

by bobtidey
Tue Feb 04, 2020 11:55 am
Forum: ESP32 Arduino
Topic: ESP32-CAM does not boot with DS18B20 on GPIO14
Replies: 4
Views: 1602

Re: ESP32-CAM does not boot with DS18B20 on GPIO14

I don't know why GPIO14 would affect the boot unless it is something to do with the camera software. Maybe try it with a minimal sketch to see if that boots OK with GPIO14 pulled up. On my camera app I do use the SD card so there is little IO free. I use RXD as GPIO3 pin; just use pinMode in setup.....
by bobtidey
Tue Dec 31, 2019 4:01 pm
Forum: Hardware
Topic: ESP32-CAM Power Issue - Works with 3.3V but not with 5V
Replies: 2
Views: 3996

Re: ESP32-CAM Power Issue - Works with 3.3V but not with 5V

Everything on the board runs from the 3.3V rail. There are 2.8V and 1.2V rails but these are derived from the 3.3V rail. The only thing the 5V connection does is connect to a 1117 linear regulator to provide the 3.3V. So if the board works fine when fed directly from 3.3V then there seems to be only...
by bobtidey
Wed Dec 11, 2019 12:50 pm
Forum: Hardware
Topic: Esp32 with LED Strip and chargable battery
Replies: 8
Views: 1765

Re: Esp32 with LED Strip and chargable battery

5V power banks contain a LIPO battery, a boost circuit to generate +5V out normally via a USB A socket, and a charger circuit typically with a micro USB input. They are available in various capacities from 2500maH upwards. So you can connect a standard phone type charger into the micro socket for ch...
by bobtidey
Fri Nov 15, 2019 10:09 pm
Forum: Hardware
Topic: UART & pins typically used by USB bridge?
Replies: 2
Views: 1314

Re: UART & pins typically used by USB bridge?

I don't know about this board but many dev boards put a series resistor between the TX of the bridge and the cpu RX. This allows an external signal to override it without causing a conflict. The TX from the cpu to the RX of the bridge is not a problem. The resistor used can be quite low (e.g. 470 Oh...
by bobtidey
Fri Sep 13, 2019 12:38 pm
Forum: Hardware
Topic: sppiffs using up a lot of space
Replies: 9
Views: 2884

Re: sppiffs using up a lot of space

There does seem to be an issue with SPIFFS slowing down appending onto large files and ultimately failing. So maybe the thing to do is to have a series of files each capable of holding say 256 records. Indexing would still be pretty straightforward as the high byte of the index would select the file...
by bobtidey
Fri Sep 06, 2019 11:06 am
Forum: Hardware
Topic: sppiffs using up a lot of space
Replies: 9
Views: 2884

Re: sppiffs using up a lot of space

Why not use 1 file for all the records to maximise space efficiency?

Decide on your maximum record size.
Block in file is Length (4 bytes) + max size.
Seek to record position (n x (4 + max Size)
Read or write length + data
by bobtidey
Mon Aug 05, 2019 9:36 am
Forum: ESP32 Arduino
Topic: Esp32-arduino-fuel gauge
Replies: 3
Views: 1491

Re: Esp32-arduino-fuel gauge

I think you need to say a little bit more about where you think you need help. Like 1) Hardware interfacing 2) Basic development environment set up 3) Basic software development to set up and periodically read gauge 4) Web development (assuming that is a phone display) or 4) Local display onto scree...
by bobtidey
Sat Jul 27, 2019 9:53 am
Forum: Hardware
Topic: I2C transmission errors. Rounded I2C clock edge from ESP module?
Replies: 6
Views: 2138

Re: I2C transmission errors. Rounded I2C clock edge from ESP module?

Are you using x10 probes to view these signals? A x1 probe has significant capacitance and could well explain the rise time.
by bobtidey
Mon Jun 10, 2019 1:46 pm
Forum: ESP32 Arduino
Topic: Alexa interaction with ESP32 chip
Replies: 2
Views: 1674

Re: Alexa interaction with ESP32 chip

Piggybacking on an existing Alexa integration would work for a personal project but might look 'unprofessional' if you are marketing this a a product. If this didn't worry you then I don't know if there any legal implications. One can use intermediary services like IFTTT but that complicates set up ...

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