Jan Dupal

VP of Engineering at Exponea interested in distributed systems, PL theory, Data Analytics and IoT.

[Jan Dupal @JanDupal]

The BikePaper project was started to scratch my own itch – my cycling GPS isn’t suited for long bikepacking rides, because of its short battery life. So I started building my own around summer 2019.

[Jan Dupal @JanDupal]

@NejiBike Love it!

Couple years ago I did my take on e-ink + GPS as bicycling navigation. Would you mind opening up your DMs? I’d like to know more about your project – I am bit tempted to resurect mine.

https://t.co/BaeQuiNGab

[Jan Dupal @JanDupal]

The BikePaper project was started to scratch my own itch – my cycling GPS isn’t suited for long bikepacking rides, because of its short battery life. So I started building my own around summer 2019.

[Jan Dupal @JanDupal]

@JakubOnderka @jakubnesetril Podepsáno. Dík za iniciativu!

[Jan Dupal @JanDupal]

@chiptronCZ Je to tak. Co jsem viděl pár displayů od @GoodDisplayCN, tak buď mají teploměr interně nebo připojitelný externě. Ta “kapalina” uvnitř displaye je podle všeho víc “líná” při nižší teplotě. Skoro se divím, že se tomu okolo 0 °C chce – pro dost eInků je to spodní hranice provozu.

[Jan Dupal @JanDupal]

@azeem Feb has 28 days, while Dec and Jan have 31 days. Adjusted for this different base, Feb would have 6,75 B, which is not that much of a difference.

[Jan Dupal @JanDupal]

Hey @spendeeapp, you’re a budgeting app. Why the hell are you focusing on NFTs?
In the meantime you’ve managed to lose all my transaction labels. Stop propagating money-laundering ponzu scheme and focus on where you’re actually providing value.

[Jan Dupal @JanDupal]

@chiptronCZ @KutilDomaci Krásné! Budu se těšit :)

[Jan Dupal @JanDupal]

@KutilDomaci @chiptronCZ Čirou náhodou se mi na stole válí úplně stejná bílá krabička z IKEA. Chci do ní nacpat ESPčko, změnit interval měření (ať vetráček neruší tak často). A možná do krabičky rovnou schovat MH-Z19. Za Tebe bys počkal pár měsíců – třeba se něco objeví... Nebo radši začít bastlit?

[Jan Dupal @JanDupal]

@oakdevtech Hey, got the same hot plate. What’s your procedure around it?
Are you using it just as a pre-heat and then reflow with hot air right on the plate? I was experimenting with impromptu cover for the hot plate to catch more heat and skip hot air, but got inconsistent results.

[Jan Dupal @JanDupal]

@zmerta Zní to jako super téma. Rád se přidám.

[Jan Dupal @JanDupal]

@daveake How long airtime & what bitrate is required to TX one still?

[Jan Dupal @JanDupal]

@GoodDisplayCN Hi!
I was looking at the 2.9” DES, but the aspect ratio makes it too narrow in portrait orientation. Still hoping that GDEW027W3-T will become available in DES variant including the touch screen. Any plans for that?

[Jan Dupal @JanDupal]

The BikePaper project was started to scratch my own itch – my cycling GPS isn’t suited for long bikepacking rides, because of its short battery life. So I started building my own around summer 2019.

[Jan Dupal @JanDupal]

@stibi V @exponea/@bloomreach_tm podobně jako píše @koraalkrabba:
1) Stáhni si git repo s naším toolingem (Helm-like)
2) Nainstaluj závislosti přes pip
3) Přes gcloud command se přihlaš
4) Spusť CLI tool, který se postará o zbytek
5) A přečti si tady naše best-practices a guidelines.

[Jan Dupal @JanDupal]

@KutilDomaci Podle GitHub username odkazovaného na Tindie to bude @Mcer12.

[Jan Dupal @JanDupal]

@NotTheWorstDev @pi0bikecomputer @adafruit @Raspberry_Pi @ssci @azumotech Thanks @NotTheWorstDev! Now all I need is to suppress the urge to buy all of them at once :D

[Jan Dupal @JanDupal]

@pi0bikecomputer @adafruit @Raspberry_Pi @ssci @azumotech Bloody hell! I think I absolutely need that display. Thanks!

[Jan Dupal @JanDupal]

BONUS: Here's an easter bunny.

Actually, I am cheating – I've preprocessed STL model in Python doing rotation, projection, Z-order and shading, producing a set of triangles for each of 15 frames.

The FPGA "just" takes the triangle sets and rasterizes them.

[Jan Dupal @JanDupal]

With the rasterizer running on ECP5, it's time for downsizing – porting the rasterizer to smaller, cheaper and more power-efficient FPGA: ICE40 UP5K.

Right now I am reducing memory consumption. The UP5K has only 120 kbits of EBR – too little to fit whole 320x240@16b framebuffer.

[Jan Dupal @JanDupal]

@fast_code_r_us @NordicTweets @latticesemi Thanks for poking me! Here's a write up on the progress: https://t.co/L2JquyLq8o

[Jan Dupal @JanDupal]

Since December, I've prototyped a crude 2D rasterizer running on FPGA. It basically takes list of vector triangles together with their fill color and renders them as a bitmap, which can be fed to a display:
(Image credit: https://t.co/kqHuo0X8gs)
CC @fast_code_r_us