Jul 19, 2014

A chart recorder printing text

Chart recorders were pretty neat devices to graph time curves of analog values, such as temperature changes. My dad had still a pair of MFE 4144 thermal line recorders in his cabinet of replacement parts. However, the device using those modules is discontinued for now about two decades and he asked me whether I could make use of them.
Luckily, my dad found the schematics and the pin mapping of the recorder, so attaching it to a microcontroller was pretty easy. The supply voltage is 12 V; I power it from a bench power supply. It takes 5 parallel TTL signals as a forward speed selection (a microcontroller drives a stepper motor), and a +/-2 V analog signal for the 'pen' position. The 'pen' is actually a needle that is being heated by a resistor. The thermopaper stains in a nice blue color when having contact to that hot metal.

Hello World

Hi folks,

I'm Marvin - Marv for short - and I'm an 18 year old student of electrical engineering and computer science (2014). I created this blog in order to share my work and ideas with the world. I won't get to specific on what I'm going to post, it can be anything from artistic work, music and videos to programming, electronics and hardware hacking - and maybe even something completely different. I just don't know yet. ;)

Enjoy :)
- Marv