I am new to microcontrollers, I am so sorry if I have some stupid questions and possible ignorance. I am planning to use this development board with several modules connected:
The following are the modules that I will use and wonder if it is compatible with ESP 32 without using additional devices (logic converters, etc.) which can be connected directly with the ESP 32 without problems.
I will use external power supply to power up those modules, and will just connect the signal pins to the ESP 32, except for the LoRa module where the 3v3 of the board will power it.
Is this possible? I want to identify first what I should consider before buying anything
Edited: I for got to add the power source, so basically I will use 18650 batteries and this is the power supply module that I consider to use:
Since all of those things come from Makerlabs, they should have the required basic information on their web site.
Logic level converters are needed only if you try to mix 5V modules with 3.3V modules, and since today, the vast majority of modules and MCUs run on 3.3V, it is best to avoid 5V MCUs or sensor boards altogether.
I know nothing about Makerlabs, but Adafruit, Sparkfun, Pololu and other responsible hobby suppliers are usually very careful to state operating voltage restrictions and other unusual requirements.
Hi thank you for replying, I've read all of the basic information stated on the products' description and most of all the parts that I listed look like I know what are the operating voltage is. I am just wondering if there are some people here who had experiences with these products when using it in ESP32, if there are some additional steps before I just connect them and make them work.
The OLED, ultrasonic sensor, and LoRa seems like I will not have any problems connecting them directly with the board, as it is stated their operating voltage is, but I am not sure with the Relay Module. When I search on the net its compatibility to the ESP 32, I got mixed answers, some say it is okay (by powering it with 5v in the vcc and 3.3 V for the signal pin) and some say that it requires additional connections.
So maybe my question for now is the relay module okay to use with the board with its other modules?
The relay module product page states 5V control voltage. The logic levels on the ESP32 are less than 3.3V. So, they are not very likely to be compatible.
There are many other relay modules on the market, some specified to work with 3.3V control logic. There are also several possibilities for interfacing a 5V relay module to a 3.3V logic circuit.
However, putting together a large system with many parts is not a good place for a beginner to start with Arduino. Start small, get one thing working at a time, and move on.
rather than using separate ESP, LCD and LoRa modules consider a single module with onboard ESP32, OLED and LoRa module such as the TTGO LoRa32 SX1276 OLED - it saves wiring and problems associated with poor connections
avoid using 5V logic devices, e.g. 3.3V relays as available on EBAY, etc in UK so it is worth checking
However, I found a solution here that says that it is okay to connect the relay as long as I will write the pins LOW to actuate the relay (correct me if I am wrong). Here is the statement in the link: Controlling a 5V relay module with an ESP32 - #5 by PaulRB
may still be worth looking to see if a ESP32 with onboard LoRa is available locally - anything to reduce wired interconnections!
don't think you have specified the project, e.g. what is the ultrasonic distance sensor for?
also look for a 3.3V LCD
also how will you power the system?
We are doing a distance measurement which will have a transmitter and sender through LoRa. The receiver will have specific command to relay depending on the distance sent. And OLED will be there to read the distance values for transmitter, the same for receiver as well.
I thought the link that I showed in the OLED will be working fine with the ESP 32 since it operates in 3.3 V?
for distance measurement have you also considered TOF sensors
if you are looking a LoRa point-to-point transmission Arduino LoRa library has plenty of example code
the OLED should be OK - I had missed the details
thank you for the reply, TOF sensors sounds promising, but we might still consider using the ultrasonic sensor as it has many documentations that we can find. We manage to find a HC-SR04 variant that can be used for the esp32!
And also if you have knowledge about relays on esp32, do you think that we can still use the 5 V relay to the board using this or much better if we will use this one. We already have the former in here so I am wondering if that is till okay to use, so that we can save costs.
