You need to avoid confusing Arduino the software environment and Arduino hardware.
There is nothing unique about the Arduino hardware and they are a very cost-effective way to obtain all the hardware for what you are requesting. You don't have to build any hardware if you don't wish to.
I often use Arduino hardware (either Nano or Uno for ~3$) but write ...
I have normally used the full-swing setting but it is not critical.
The main issue is whether you are using the XTAL2 output for driving other devices (either another MPU or logic).
See page 42:
"This Crystal Oscillator is a full swing oscillator, with rail-to-rail
swing on the XTAL2 output. This is useful for driving other clock
inputs and in noisy ...
If you read the AVR datasheet, it says you can use either low power mode or full swing mode with a crystal of that frequency, but only if the AVR supply voltage is high enough. If supply voltage is too low, you can't use full swing mode then.
I noticed that many microcontrollers have an SPI. I thought I could use this along with a USB to programming it serially.
These are wildly different protocols, and building your own adapter between them is definitely a project for after you've learned a lot about microcontrollers.
On the other hand, you can just buy one:
An Arduino does not have to be a pre-fabricated board - it can be as simple as a microcontroller IC and some support components.
An eg basic Arduino Nano clone from Asia for under $US3 incl shipping gives you a few basic ICs a voltage regulator, a USB to serial interface and some support firmware to allow bootloading from USB. You gain nothing by not ...
Answer is simple: Serial.
Get yourself a UART-USB converter like this, write some code in whatever language you please in order to use a COM port for communication. Done.
Don't you worry about clock speeds and bit banging. No need to reivent the wheel.
USB and SPI are completely different and you cannot communicate between your computer and your microcontroller using SPI directly.
However in most (to not say all) of the current microcontroller eval boards you will be provided with an UART-to-USB converter, and thus you will be able to communicate with your PC using an UART.
Désoler votre Nrf24 est brulé Tu na pas mise un régulateur 3.3v
Et dans le deuxieme shema vous devez ajouter des condonstateurs
Google translate says: "Sorry, your Nrf24 is burned. You did not use a 3.3V regulator. And in the second schematic you have to add condemators [capacitors?]."
If I use this 3.7V battery, will this work well?
The actual voltage of the battery will decrease from 4.2 V to 3.3 V, as the battery slowly goes from fully charged to fully discharged. The atmega328 accepts between 1.8 and 5.5 V power, so it will work under the full range of voltage from the battery without voltage regulation.
Note however that the full 1....
ISP clock can't "interfere" with on-board clock. ISP clock is the clock for the ISP data. The MCU still needs a clock to run itself, and this clock needs to be high enough for the given ISP clock. Slower MCU clock needs slower ISP clock for sure, exact parameters are given in AVR datasheet.
The ones in the picture are standard 2.54 mm pitch.
There are many more pitches than 2 and 2.54 mm. For example have a look at the pitch selector in Mouser: https://www.mouser.co.uk/Connectors/Headers-Wire-Housings/_/N-ay0lo
I found this repository containing some design files and although the board is different from the one I'm gonna use, I'm assuming they do follow the same standard. The pitch on this one is 2.54mm. Feel free to correct me, but until then, I'll leave this as an answer.
*ddr_k &= 0xFF;
is wrong. The data direction register is 0x00 by default, so ANDing it with anything will still leave all the pins as inputs. It should be
*ddr_k |= 0xFF;
*ddr_k = 0xFF;
You need to connect all grounds: the Arduino's GND and the driver's GND. In the first place this has nothing to do with "feeding" in the sense of providing power, it is necessary to define a common voltage reference. You surely know that voltages (and digital levels are voltages) are measured against a reference, don't you?
If you power the driver and in ...