You have had this great idea for a new widget, or can see a gap in the market for an imported product, so how easy is it to set up a new electronics business in the UK? To test the water, you could just make some in your shed or import a few shipments and sell them on Ebay, (although HM Customs and Revenue are now data mining online to try and catch informal business and get more money!) but how easy is it to then create a formal business?
There are many different wireless protocols out there, but the ones that most people have heard of are WiFi and Bluetooth because these are used in devices that lots of us have, mobile phones and computers. There is a third alternative called ZigBee that is designed for control and instrumentation. What are the differences?
Most of us have PIC programmers for development, such as Microchip IDC2 or a PIC ICSP programmer such as PRESTO, which are very good at what they do. But they are not ideal for either production or field updates, because they require too much knowledge to use or need a laptop to be used in a challenging environment.
Since the advent of Windows 7, some of our customers have had problems with software updates because the update does not install successfully. These problems do not seem to happen in Vista but maybe nobody uses it!
These problems take the form of firmware mismatch or sometimes settings are not saved properly, and can affect some of our products and any other older software you may have.
A question we are commonly asked is “How do I copy a serial EEPROM chip?”. Serial EEPROMs are the memory chips found in car keys, some radios, PC motherboards and other electronics. They are usually 8 pin and retain data when the unit is switched off, which is why they are used for settings and configuration data. This is also why people want to copy them.
One feature of AVR devices that can baffle new users is the default clock setting on new AVR microcontrollers. They are set to run from their internal RC oscillator, usually 1 MHz, which throws out the timing on code samples, such as UART.
If the code is configured for an 8MHz clock and there is a 8MHz clock on the target board, you expect it to work but instead you get nothing or garbled characters. This is due to the default Internal RC. How do you change it?
PIC microcontrollers, like most modern microcontrollers, can be programmed in system (or in circuit – ICSP) rather than in a socket programmer. This has advantages in development and in production, for example, to use different firmware for different versions or to speed up production. The major benefit though is field upgrades. We can give you lots of horror stories about people who didn’t think of firmware upgrades and had to recall products to fix a bug, not a cheap option. So how do you add In System Programming to your designs?
The major factors are the electronic design of the ICSP circuit and the ICSP connector format. Let’s look at the connector format first. Most Microchip development boards (and ICD2/3 debuggers) use RJ11 connector by default, but this is a poor choice for field or production use.
The AVR microcontroller is excellent with C code because it was designed with C in mind. Atmel have also made it easy to use C in AVR Studio, as WinAVR compiler can run from within AVRStudio just like the assembler.
Only a few years ago, using C compilers involved complicated commandline instructions and make files but WinAVR more or less takes care of this for you. WinAVR is based on the free GNU-GCC compiler but is much friendlier, especially for beginners.
Microchip have scored a winner over Atmel AVR by including all the information required to program a PIC microcontroller in one Hex file. This includes code, EEPROM data, User bytes (User ID) and most importantly, configuration words.
This makes it much easier to transfer the project from development to production or between engineers, as all the information needed is in one file. Atmel, now they have been taken over by Microchip, have belatedly added an ELF production file format that can do the same thing. See this post for details – Producing AVR and ATxmega ELF production files So, what is this PIC file format?
PIC microcontrollers are manufactured by Microchip
They cover a huge range of devices, from tiny 8-bit microcontrollers to 32-bit advanced PIC32 devices. All PIC microcontrollers use Harvard architecture, which means that they have separate buses for data and instructions. If a device is called an 8-bit microcontroller, this means that its data bus is 8-bit, a 16-bit device has a 16-bit data bus and, guess what, a 32-bit microcontroller has an 32-bit data bus. Continue reading “PIC Microcontroller” »
Microcontrollers, training, electronics and coding
