When comes time to design a circuit with a microcontroller, there are many aspects to consider.
How many I/O pins are required, is there enough digital to analog output, is there enough memory for the program… All these aspect are solved in a minute just by choosing at the catalog of any microcontroller manufacturer.
But the most critical aspect of any electronics project are the time and the money.
Let’s say you work on a minimally professional project for your own or for a customer.
The time affected elements are the software design and the printed circuit board (pcb) design. One week to develop your software, one more week to draw your pcb, one more week to wait for the pcb manufacturing, while you create the bill of material, find components suppliers and place the components order.
If you are lucky, you receive your bare pcb at the end of the 3rd week.
Money affected elements: you possibly ordered 10 units of this bare pcb for approximately 500$, and you possibly ordered enough components to assemble these 10 circuits for 200$. You are now working on this project since 3 weeks, may be 4 weeks considering inevitable delays, so add 4 weeks of salary to the project. Let’s say 2400$. Since you are using surface mount (SMT) components in your design, don’t forget to add a stereo-microscope, $1000, a regulated soldering iron with wave tip, 150$, plus miniature tools, tweezer, flux, flux remover,…, 50$.
There you start assembling your first circuit as a prototype, hoping not too many mistakes on the pcb to minimize the patches. You achieve soldering the pcb and start flashing the microcontroller and attempt debugging the software. At the end of the week everything seems stable and you may complete some other pcb for your customer and keep 5 pcb as spare.
You have now reach 5 weeks of work for 3000$ in salary and close to 1900$ in related fees, assuming you are quite professional in all the aspect of electronics design and software development and not adventuring yourself for the first time with SMT components.
Obviously, I did not consider your personal computer, neither the pcb design software that you might possibly own. If not, add it to the total, 1500$, for a total of 6400$.
One other way to attack this design situation would have been to consider pre-assembled electronics modules.
Since many years you may find on the market different microcontroller peripherals like opto-isolated relay board, servo control board, motor control board, and sensors of all kind.
You may also find market pre-assembled unit of SMT microcontrollers, from 20$ to $100, depending on number of I/O pins.
The major problem I encountered with these is that they are all mounted on DIP pins forcing me to use or design a carrier pcb to connect to them. Not really time saving solution. They are more suitable for prototyping on breadboard.
One interesting discovery I made is the circuit MT0401 from Marcius Technologies Inc.
It’s like a miniature pre-assembled microcontroller built around the smallest package of the PIC18F452 from Microchip, having its own carrier board. The circuit includes one LED on each I/O pins, acting as a 32 real time logic probes. The circuit is also easily attachable with professional Snaptrack. It’s having removable and reusable section. It’s an open design, allowing user to choose his own header for connections. It’s also very easy to supply.
The logic probes are helpful while debugging and the same circuit is directly integrated in the delivered project as a brain circuit. No other pcb required, you flash it, you connect it to your peripherals and that’s it. Not bad for 89$.
Considering all the time and money saving aspect of this product, you may achieve your project in one week. I’ll let you evaluate the total saving.
How many I/O pins are required, is there enough digital to analog output, is there enough memory for the program… All these aspect are solved in a minute just by choosing at the catalog of any microcontroller manufacturer.
But the most critical aspect of any electronics project are the time and the money.
Let’s say you work on a minimally professional project for your own or for a customer.
The time affected elements are the software design and the printed circuit board (pcb) design. One week to develop your software, one more week to draw your pcb, one more week to wait for the pcb manufacturing, while you create the bill of material, find components suppliers and place the components order.
If you are lucky, you receive your bare pcb at the end of the 3rd week.
Money affected elements: you possibly ordered 10 units of this bare pcb for approximately 500$, and you possibly ordered enough components to assemble these 10 circuits for 200$. You are now working on this project since 3 weeks, may be 4 weeks considering inevitable delays, so add 4 weeks of salary to the project. Let’s say 2400$. Since you are using surface mount (SMT) components in your design, don’t forget to add a stereo-microscope, $1000, a regulated soldering iron with wave tip, 150$, plus miniature tools, tweezer, flux, flux remover,…, 50$.
There you start assembling your first circuit as a prototype, hoping not too many mistakes on the pcb to minimize the patches. You achieve soldering the pcb and start flashing the microcontroller and attempt debugging the software. At the end of the week everything seems stable and you may complete some other pcb for your customer and keep 5 pcb as spare.
You have now reach 5 weeks of work for 3000$ in salary and close to 1900$ in related fees, assuming you are quite professional in all the aspect of electronics design and software development and not adventuring yourself for the first time with SMT components.
Obviously, I did not consider your personal computer, neither the pcb design software that you might possibly own. If not, add it to the total, 1500$, for a total of 6400$.
One other way to attack this design situation would have been to consider pre-assembled electronics modules.
Since many years you may find on the market different microcontroller peripherals like opto-isolated relay board, servo control board, motor control board, and sensors of all kind.
You may also find market pre-assembled unit of SMT microcontrollers, from 20$ to $100, depending on number of I/O pins.
The major problem I encountered with these is that they are all mounted on DIP pins forcing me to use or design a carrier pcb to connect to them. Not really time saving solution. They are more suitable for prototyping on breadboard.
One interesting discovery I made is the circuit MT0401 from Marcius Technologies Inc.
It’s like a miniature pre-assembled microcontroller built around the smallest package of the PIC18F452 from Microchip, having its own carrier board. The circuit includes one LED on each I/O pins, acting as a 32 real time logic probes. The circuit is also easily attachable with professional Snaptrack. It’s having removable and reusable section. It’s an open design, allowing user to choose his own header for connections. It’s also very easy to supply.
The logic probes are helpful while debugging and the same circuit is directly integrated in the delivered project as a brain circuit. No other pcb required, you flash it, you connect it to your peripherals and that’s it. Not bad for 89$.
Considering all the time and money saving aspect of this product, you may achieve your project in one week. I’ll let you evaluate the total saving.
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