Search found 38 matches

by bobtidey
Mon Mar 18, 2019 11:52 am
Forum: Hardware
Topic: Explanation on ESP32 DevitKitV1 circuitry
Replies: 2
Views: 1996

Re: Explanation on ESP32 DevitKitV1 circuitry

When either DTR,RTS are both high or both low then EN and GPIO0 will both be high. It is done this way to ensure that the chip will run normally under either of these conditions. When DTR is high and RTS is low then GPIO0 is high and EN is low. Similarly when RTS is high and DTR is low then EN is hi...
by bobtidey
Mon Dec 17, 2018 9:05 am
Forum: Hardware
Topic: How to power the 3.3V ESP32 from a 3.7V Li-ion battery?
Replies: 14
Views: 19000

Re: How to power the 3.3V ESP32 from a 3.7V Li-ion battery?

Little bit more info on the XC6203 LDO regulators. The maximum peak current is 600mA with the sustained output current of 400mA. I use the E series which has no built in current limiter to ensure that doesn't kick in. With a 220uF miniature SMD output capacitor I haven't seen any significant brown o...
by bobtidey
Fri Dec 14, 2018 8:49 am
Forum: Hardware
Topic: How to power the 3.3V ESP32 from a 3.7V Li-ion battery?
Replies: 14
Views: 19000

Re: How to power the 3.3V ESP32 from a 3.7V Li-ion battery?

I use xc6203 LDO regulators with LIPO batteries. These have a drop out of around 150mV at the normal supply currents and also a fairly low quiescent current of around 8uA to minimise battery drain. As the modules will work happily down to 3.0V this means the batteries are good down to about 3.3V whi...
by bobtidey
Sat Dec 01, 2018 11:18 am
Forum: ESP32 Arduino
Topic: Calling function from inside ISR doesn't work
Replies: 3
Views: 2074

Re: Calling function from inside ISR doesn't work

Difficult to see what is going on as code example seems to be badly formatted onto one line.

It does look like there might be a missing semicolon after the digitalWrite in morseDebug
by bobtidey
Fri Nov 16, 2018 11:48 am
Forum: ESP32 Arduino
Topic: ESP32 and solar cells
Replies: 5
Views: 4736

Re: ESP32 and solar cells

I think something like this would work. LP3470Reset.jpg Battery includes any charging / protection circuit you are using. When voltage is above 3.6V RST is high, MOSFET turns on and connects circuit ground back to battery ground. Capacitor controls delay on releasing RST after battery goes above 3.6...
by bobtidey
Thu Nov 15, 2018 10:45 am
Forum: ESP32 Arduino
Topic: ESP32 and solar cells
Replies: 5
Views: 4736

Re: ESP32 and solar cells

Most ESP32 modules have the EN / Reset pin internally pulled high through a 10K resistor. So grounding this pin will draw a significant current (330uA) despite the ESP32 being off. The ESP8266 is slightly superior in this respect as it has separate EN and RST pins and the EN does not have an interna...
by bobtidey
Sun Oct 28, 2018 10:52 am
Forum: Hardware
Topic: Selecting a logic analyzer
Replies: 5
Views: 2496

Re: Selecting a logic analyzer

Yes. Pulseview works well for medium speed analysis. As well as the common 8 bit logic hardware available you can also use CY7C68013A dev boards which give 16 bit operation. See https://www.thingiverse.com/thing:2153437 for a 3d printed enclosure for this. Note that you will struggle to look at USB ...
by bobtidey
Sun Oct 28, 2018 10:42 am
Forum: Hardware
Topic: ADC Input Resistance?
Replies: 1
Views: 2774

Re: ADC Input Resistance?

I think the ADC inputs have the same characteristics as the normal IO pads

https://www.espressif.com/sites/default ... eet_en.pdf

e.g. 50nA max leakage current
by bobtidey
Fri Oct 19, 2018 10:20 am
Forum: ESP32 Arduino
Topic: Changing TCP listening port not possible on the ESP32
Replies: 3
Views: 1972

Re: Changing TCP listening port not possible on the ESP32

I see now the port argument has been added into to later versions than I had.

That's good. Time to update.
by bobtidey
Thu Oct 18, 2018 11:24 am
Forum: ESP32 Arduino
Topic: Changing TCP listening port not possible on the ESP32
Replies: 3
Views: 1972

Re: Changing TCP listening port not possible on the ESP32

begin does not take a parameter.

I think you can just repeat the instance using myServer(myPort); before doing the begin.

Go to advanced search