Putting a ‘bare’ (3.3V) ATmega, ESP8266 or STM32 on a breadboard is doable (although for ESP8266 there are very few options) because there are rather basic boards available for these MCU’s that are breadboard friendly and require only the voltage regulator and one or more LED’s to be removed for low power / reliable measurements.
For ESP32 I still have not been able to find a suitable board that is breadboard friendly and does not have a USB to serial chip and not have battery charging support integrated on the board. For boards that have USB to serial and battery charging support integrated, these components are (very) difficult to remove and often require a microscope to do the job.
For (3.3V) ATmega328 an Arduino Pro Mini is the most practical.
For STM32 a basic ‘blue pill’ board (STM32F103C8) can be used.
For ESP8266 there are very few options (such boards) available. I use this one: ESP8266 SMD Adapter Board R2 [version] - ElectroDragon (it’s voltage regulator has a quescent current of up to 90uA so worth removing for low power).
For ESP32 I have not found any similar option which fits a normal breadboard (and which has pull-ups/downs and 2 switches required for normal operation already included).
That is a real nice charger with an informative display. In addition to Liitokala Lii-402 the Folomov-A4 also has 250mA and 3A charging modes and it can charge 4 cells with 2A at the same time (and costs almost 3 times as much).
Good reviews of the LiFeSO4 suitable A4 and Lii-402 chargers:
Folomov-A4: Review of Charger Folomov A4
Liitokala Lii-402: Review of Charger LiitoKala Lii-402
Before you ask, the DCDC converter is not the reason. I also make measure on the 3.3V directly with a 3.3V source.`
So the ‘DCDC converter’ (regulator ?) was removed or otherwise disconnected from the 3.3V supply to the processor and RFM95 when you measured the current ?
I would also suggest that unless you want to re-work that board, by removing or replacing the regulator, your never going to get sleep current below (typically) 90uA.
Hello,
I have a project with a communication Lora, and different sensors with low consumption.
But with an arduino pro mini + rfm95w, I don’t have enough space on the microcontroller:
text section exceeds available space in board
Le croquis utilise 33216 octets (108%) de l'espace de stockage de programmes. Le maximum est de 30720 octets.
Les variables globales utilisent 1852 octets (90%) de mémoire dynamique, ce qui laisse 196 octets pour les variables locales. Le maximum est de 2048 octets.
Croquis trop gros ; vois http://www.arduino.cc/en/Guide/Troubleshooting#size pour des conseils de réduction.
Erreur de compilation pour la carte Arduino Pro or Pro Mini
I can’t reduce my code. The library use most of the space.
Do you have suggestions for a board with very low consumption and more space than an atmega328p ?
The Nano Every which is an ATmega4809 has the space.
Or if you look at the options for the library you can turn off the Class B support and it may then fit on your Pro Mini - the forum has many questions exactly like this so search & reading may be a quick win.
If your using the Arduino IDE, you can download the core for the NanoEvery\ATmega4809 and check if the program you have (and the sensor libraires used) compiles OK and how much space the entire program uses.
Hello! I have started with PRO NANO and LoRa XL1278 module. Is it possible to put this module in sleep mode (<1 mA) ? In my circuit is always about 20 mA! The connections are like in this page:
Could somebody check the code:
< radacted - do not post files when formatted text works just as well but doesn’t require a download >
