Where I describe how to use the GNU Linker wrapper capability and variable arguments to enhance printf() for better debugging.
This recent post fascinated me. It describes a feature of the GNU linker called wrapping which allows you to replace an existing symbol (command) with a new version. The example describes adding a timestamp to printf(). While, for me, this might be a solution looking for a problem, I really liked the idea. And at the very least wanted to add the concept to AVR_C.
Where I share various observations as to how to use the Pico with the Arduino software framework and the legacy (~1.8.19) Arduino IDE.
While most RP2040 boards will have a Reset button, the Pico does not. Why? To save costs. It also has a micro-USB connector instead of a USB C connector for the same reason. The single best way to ensure your Pico uploads properly (or more accurately) the Arduino IDE uploads to the Pico, properly is to press and hold the Boot/Sel button then unplug and plug-in the Pico. This can be required a great deal when testing I2C and the unplug/plug-in is a bit of a pain.
Where I explore how to use the Pico’s abundance of I2C interfaces to create 2 separate I2C instances.
I have been using the Arduino framework and legacy IDE (1.8.19, not the 2.0 version) to develop code on the Raspberry Pi Pico. The Pico is an incredible board, well worth using due to its outstanding price/performance ratio. For only $4, you can buy a very powerful, very well documented and easily available microcontroller. With the addition of the Arduino framework, it makes using the Pico a simple decision for a lot of Uno projects..
Where I demonstrate how to use a GitHub repository to develop a data logger with the Arduino Uno to measure and record analog values. In this example, I will be measuring voltage, however the same approach could be used to measure capacitance, temperature, or light etc.
Where I describe how to improve the performance of your programs by accessing the input/output (I/O) ports on the Arduino Uno, natively.
The Arduino framework and Uno hardware has performed an admirable job in abstracting much of the complexity of the ATmega328P into something which is easier to understand. This approach works well for a beginner in microcontrollers and embedded C programming. Once you begin to understand how the ATmega328P works, its not unusual to find the Arduino simplification is holding you back.
Where I demonstrate different methods of measuring a servo pulse to ensure it meets requirements.
In the entry on servos I discussed the specific pulse requirements to make a servo move. In a nutshell, a servo needs a positive pulse .5ms to 2.3ms in a 60Hz signal. Or to put it another way, it requires a 60Hz signal with a duty cycle ranging from 3% to ~14%.
Reference page for Bloom configuration and commonly used avr-gdb commands.
environments:
default:
debugTool:
name: "atmel-ice"
target:
name: "atmega328p"
physicalInterface: "debug-wire"
disableDebugWirePreDisconnect: false
manageDwenFuseBit: true
variantName: "atmega328p-pu"
debugServer:
name: "avr-gdb-rsp"
ipAddress: "127.0.0.1"
port: 1442
insight:
enabled: true
set history save on
set history size 10000
set history filename ~/.gdb_history
file main.elf
target remote :1442
set listsize 0
define cll
make
load main.elf
mon reset
refresh
list
end
Where I describe how to use the servos() interface in AVR C.
Servos are a powerful addition to the embedded programming toolkit as they enable motion. Not high-speed motion as in a electric motor, however, motion which can be easily controlled and typically in an arc or as angles. Servos are much more precise as to how they can move in comparison to electric motors. See Sources above for a few example tutorials as to how to use them.
Where I describe how to develop use pointers in AVR_C.
Pointers are introduced by “K&R” with the following comment “Pointers have been lumped with the goto statement as a marvelous way to create impossible- to-understand programs.” While pointers are simple in nature, they can become quite complex, quickly. I recommend going through the examples on this page, slowly and methodically as well as making changes and determine if the change had the effects you believed it would. I also recommend having a C Language reference manual open as well, as I won’t got through the usage.
Where I demonstrate the value of coding efficiency to reduce the cost of hardware.
In the another entry, I discussed code size, program space and RAM requirements and why they matter. Here are my thoughts from that page: