Hi everyone, and thank you for reading my post.
I'm wanting to use an Arduino Pro-Mini in a project which is going to be powered by 2 x li-ion cells, so I'm going to be powering it from the RAW pin. The on board linear 3.3V regulator is thus going to be employed to power the Arduino. I'm wondering if the VCC pin on the Arduino will be a suitable source for a 3,3V supply to power a small OLED display? The on board regulator I believe is 100mA capable and the OLED display can use a maximum of 70mA when all cells are lit. In practice this is not going to be the case, I'd say 25% lit will be the most it's likely to use. Unfortunately I cannot get any information as to the current usage at partial levels like that, it only quotes maximum values. I have desoldered the power LED from the Arduino to shave a bit of current off but I think I may be sailing a little too close to the edge of the world. I don't really want to have to put another 3.3V regulator into the mix as I'm trying to keep component count down to a minimum. Fortunately the Arduino is not using any other output lines for any low(ish) impedance tasks and I'm seeing 8.5mA typical running current during operation without the OLED screen and 46-56mA with the OLED screen attached and displaying a typical amount of lit cells but the regulator on the Arduino is getting pretty hot so I'm hoping a small heat sync attached to the regulator would be enough keep things safe.
I'd appreciate any advice or suggestions on this from the experts.
Many thanks,
M
I'm wanting to use an Arduino Pro-Mini in a project which is going to be powered by 2 x li-ion cells, so I'm going to be powering it from the RAW pin. The on board linear 3.3V regulator is thus going to be employed to power the Arduino. I'm wondering if the VCC pin on the Arduino will be a suitable source for a 3,3V supply to power a small OLED display? The on board regulator I believe is 100mA capable and the OLED display can use a maximum of 70mA when all cells are lit. In practice this is not going to be the case, I'd say 25% lit will be the most it's likely to use. Unfortunately I cannot get any information as to the current usage at partial levels like that, it only quotes maximum values. I have desoldered the power LED from the Arduino to shave a bit of current off but I think I may be sailing a little too close to the edge of the world. I don't really want to have to put another 3.3V regulator into the mix as I'm trying to keep component count down to a minimum. Fortunately the Arduino is not using any other output lines for any low(ish) impedance tasks and I'm seeing 8.5mA typical running current during operation without the OLED screen and 46-56mA with the OLED screen attached and displaying a typical amount of lit cells but the regulator on the Arduino is getting pretty hot so I'm hoping a small heat sync attached to the regulator would be enough keep things safe.
I'd appreciate any advice or suggestions on this from the experts.
Many thanks,
M
