NRF5340 VS NRF52840
Conclusion of NRF5340 VS NRF52840
When compared to the nRF52840 SoC, the 0 dBm TX current of NRF5340 is 3.4 mA, while the RX current is only 2.7 mA, resulting in a reduction of 29% and 41%, respectively. The RX sensitivity of the nRF5340 is -98 dBm, which is 3 dB better than the nRF52840. This means that the nRF5340 has 3 dB better sensitivity while utilizing 41% less current.
If you want to learn more, try to follow the below link to see the article about them.
https://www.utmel.com/componen....ts/nrf5340-vs-nrf528


If you are interested in these products, try to follow the below link to see them.
https://www.utmel.com/productd....etail/nordicsemicond

The ADS1115 and ADS1015 4-channel breakout boards are perfect for adding high-resolution analog to digital conversion to any microprocessor-based project. These boards can run with power and logic signals between 2v to 5v, so they are compatible with all common 3.3v and 5v processors. As many 4 of these boards can be controlled from the same 2-wire I2C bus, giving you up to 16 single-ended or 8 differential channels. A programmable gain amplifier provides up to x16 gain for small signals.
If you want to learn more, try to follow the below link to see the article about them.
https://www.utmel.com/componen....ts/difference-betwee

If you are interested in these products, try to follow the below link to see them.
https://www.utmel.com/productd....etail/adafruitindust

RP2040, ATMEGA328, ESP32, and STM32 are all microcontrollers. So I want to figure out the differences between them.
What is the difference between ESP32 and STM32?
As others have mentioned, ESP32 can be utilized if you're only interested in connectivity (BLE and WiFi), whereas STM32 has a wider range of applications. STM32 + Other chip-sets are frequently used in products to accomplish communication and sensing applications.
If you want to learn more, try to follow the below link to see the article about RP2040 VS ATMEGA328 VS ESP32 VS STM32.

https://www.utmel.com/componen....ts/rp2040-vs-atmega3

Short introduction of USB DB9
The DB9 connector (originally named DE-9) is an analog socket, with 9 pins, from the D-Subminiature (D-Sub) connector family. The DB9 has the smallest "footprint" of the D-Subminiature connectors. The prefix “D” represents the D-shape of the connector shell. The DB9 connector is mainly used in serial ports, allowing asynchronous data transmission according to the RS-232 standard (RS-232C). Note that there are DB9-DB25 adapters that easily convert a DB9 socket to DB25 and vice versa.

If you want to learn more, try to follow the below link to see the article about DB9.
https://www.utmel.com/componen....ts/db9-tripp-lite-in

Overview of ULN2003A
The ULN2003A is a Darlington array with seven open collectors Darlington pairs and common emitters that can handle high voltage and current. Each channel can handle peak currents of 600 mA and is rated at 500 mA. For inductive load driving, suppression diodes are added, and the inputs are pinned opposite the outputs to simplify the board layout.
If you are interested in that, try to follow the below link to learn more:
https://www.utmel.com/productd....etail/stmicroelectro
Does anyone interested in batteries? If so, you can look the article
about E91
https://www.utmel.com/componen....ts/e91-energizer-aa-