Search found 16 matches

by dk-
Thu Oct 15, 2020 8:22 pm
Forum: Software Library
Topic: Discrete fourier transform
Replies: 0
Views: 266

Discrete fourier transform

I made a program that functions like the regular plot, but prints the discrete fourier transform of the supplied function. (Function can have arguments as menuvars). The number of bins needs to be a power of two, and 1024 seems to be the max that the DM42 can handle. Free42 can go higher. The code b...
by dk-
Fri Oct 09, 2020 10:11 am
Forum: DM42
Topic: WIP: 3D graphs
Replies: 2
Views: 280

Re: WIP: 3D graphs

My current solution can be made fairly general purpose since it uses affine transformations to setup a view port with perspective. But instead it's fairly slow...so it might be a bit too slow when running on battery.
by dk-
Thu Oct 08, 2020 7:58 pm
Forum: DM42
Topic: WIP: 3D graphs
Replies: 2
Views: 280

WIP: 3D graphs

Figured I'd share a picture of some work-in-progress code.

Is there already a solution for 3D graphs done for the DM42 or should I keep digging this hole? :)

Image
by dk-
Wed Oct 07, 2020 7:45 pm
Forum: DM42
Topic: DM42 with homemade printer
Replies: 46
Views: 2757

Re: DM42 with homemade printer

I've updated the repository (https://github.com/dankar/redeye) with a schematic, some notes on the schematic, and updated the code to correctly handle overflows (the printer will print the overflow character, same as the real HP printer).
by dk-
Sat Oct 03, 2020 9:21 pm
Forum: DM42
Topic: DM42 with homemade printer
Replies: 46
Views: 2757

Re: DM42 with homemade printer

I should think that the graphical output of Christoph Gießelink's HP82240B Printer Simulator already uses accurate font information, and it includes the source code, so you could "borrow" the font bitmaps from that. I've already done the font, but thanks for the tip. I didn't want to take...
by dk-
Sat Oct 03, 2020 8:06 pm
Forum: DM42
Topic: DM42 with homemade printer
Replies: 46
Views: 2757

Re: DM42 with homemade printer

Can the DM42 send data to this printer at a rate that takes advantage of the line printer mechanism's speed, or is it limited to the 82240-compatible data rate? I don't know actually. The thermal printer I have is limited to 19200 baud, and however long it takes to print. I am also sending everythi...
by dk-
Sat Oct 03, 2020 5:37 pm
Forum: DM42
Topic: DM42 with homemade printer
Replies: 46
Views: 2757

Re: DM42 with homemade printer

Here are two pictures of two different self-test prints with different print contrast : https://www.dropbox.com/s/opfdr80plfidfbs/IMG_20201003_141407.jpg?dl=0 https://www.dropbox.com/s/qu1ksudzzpx9hgc/IMG_20201003_141353.jpg?dl=0 Many thanks! Here is the updated code: https://github.com/dankar/rede...
by dk-
Sat Oct 03, 2020 1:34 pm
Forum: DM42
Topic: DM42 with homemade printer
Replies: 46
Views: 2757

Re: DM42 with homemade printer

If I can be so bold as to borrow my thread back from the discussion on geopolitical definitions, I have a small update on my printer :) I had some time today to write some more code. I now have the code running on a single Arduino Uno and it uses the correct font! That is, as far as I could decipher...
by dk-
Fri Oct 02, 2020 1:33 pm
Forum: DM42
Topic: DM42: IR-receiver photodiode specs?
Replies: 6
Views: 357

Re: DM42: IR-receiver photodiode specs?

Regarding the pulses: When I built my homemade printer I used an IR transistor that had fairly slow fall and rise times (something around 15us for 90% <-> 10% transitions), almost on the edge of detecting the 32768Hz carrier frequency. But keep in mind that it's entirely up to you if you want to det...
by dk-
Sun Sep 27, 2020 9:12 pm
Forum: Software Library
Topic: plot_thomas.raw with up to two solutions
Replies: 0
Views: 180

plot_thomas.raw with up to two solutions

Hi, I made some small modifications to Thomas' plot-program (I hope you don't mind!) to allow finding up to two solutions. It does this by searching below AXIS and above AXIS, meaning that the placement of AXIS is crucial to get good results. For example: 00 { 42-Byte Prgm } 01▸LBL "HEART"...