Timeline for CH340 3.3v stability
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 23, 2017 at 13:20 | comment | added | frarugi87 | @John see my answer; in any case your 3.3V varies not only from host to host, but also during the time. If you want a precise measure, use an external reference, otherwise you'll have to calibrate the internal one. And if you don't want to use a high reducing of the input voltage, use the trick I wrote in the answer (measure the reference and then use that measure to compensate) | |
| Nov 23, 2017 at 2:39 | comment | added | John | I wanted to try the 3.3v as the input voltage from USB (VCC) differs on each host it's plugged into. I'm wanting to measure an external battery voltage. It goes through a voltage divider with high precision resistors, but if I divide it down to a max of 1.0 volts, I have to use very high precision resistors for the divider circuit. | |
| Nov 22, 2017 at 14:02 | answer | added | frarugi87 | timeline score: 1 | |
| Nov 22, 2017 at 9:58 | comment | added | Jot | The internal analog voltage reference of 1.1V is better. That voltage can be 1.0 to 1.2V so you have to determine it for each board (just once). After setting the analogReference to 1.1V, you can measure the actual voltage at the aref pin: pighixxx.com/test/portfolio-items/nano Why do you need a reference of 3.3V? Is it for a analog sensor running at 3.3V? | |
| Nov 22, 2017 at 4:18 | comment | added | John | Very little, just that it's a 3.3v LDO rated to 25mA | |
| Nov 22, 2017 at 4:16 | comment | added | Ignacio Vazquez-Abrams | Datasheet says? | |
| Nov 22, 2017 at 4:15 | history | edited | dda | CC BY-SA 3.0 |
deleted 5 characters in body
|
| Nov 22, 2017 at 4:13 | review | First posts | |||
| Nov 22, 2017 at 4:14 | |||||
| Nov 22, 2017 at 4:10 | history | asked | John | CC BY-SA 3.0 |