Q: Why a PIC18F25K22 instead of XYZ?A: I’m used to PICs and I have all the fun to design my own boards!Q: Why PicBASIC?A: I’ve learned C with TurboC 20 years ago. It’s been now 20 years I’m programming VBA and VB.NET. I’m just too lazy to go back, don’t...
I just registered domain name pdpii.com ;)Now I'm thinking about a family of modules (main processor one and many peripherals) that shares the same bus ( breadboard friendly Q-bus extended or BBFQ-bus+ ; ) - all open source of course :)Using such modules...
I discussed the Spikeputor and its Apple ][ interface at KansasFest 2021 (link), a conference for devoted Apple ][ (and ///) fans. Here's the talk, which I pre-recorded for the virtual event, followed by a live Q&A session:
Below the cabling of a bit slice for the no diodes "disconnected" design as used in the Super Micro Relay Computer (https://hackaday.io/project/167895-super-micro-relay-computer), including the cabling of the Q register bit for the non zero detection...
When I show my PV system to my friends, they often ask following questions:Q: How much did your PV system cost ?A: The total budget is close to 14 000 €Q: What about the ROI (Return On Investment) ?A: It will take 20 years to amortize the...
When I was working on one of my projects I needed to filter analog signal above 10Hz... or above 1000Hz... whatever. Well I decided to add a second order low pass filter instead of simple first order to get rid of that ugly and nasty noise :)General...
My previous turbine 3D model was quite large. Let’s only take the first four layers of the GCODE to help understand the coordinate synchronization algorithm. Here is an algorithm to find the line going from a point on layer one to a point on layer 4...
Noisy Regen SimulationAlan Yates (http://www.vk2zay.net/article/128) has stripped down the Franklin Audion circuit to its basics and taken the audio off the emitters rather than the tuned circuit. This seems to make more sense to me:(Note that the 47n...
If we try to summarize what we have seen so far: Arithmetic operations on arbitrary analog values are better performed using digital numbers to get a repeatable accuracyUnsigned integer digital numbers are represented as base 2 (binary) numbers using...
Q: What's the overall cost of this thing?A: A quick back-of-the-envelope estimate would be:laser: 250€microscope objective: 150€diffraction grating: 125€ filter+DIC-mirror: 75€OAP-mirrors: 350€elliptical mirrors: 150€lens...
Last time, I talked about how I shifted most of the heavy calculation work for rasterization into the per-triangle preparation, the PreCalc block. In this post I'll walk through some of the steps from formula to implementation.At its heart are the following...
2020-10-27 Ordered modules to play with: AZDelivery ADS1115 ADC Analog to Digital Converter 16bit 4-Channel Module (pack of 3)AZDelivery I2C 0.96-inch OLED Display SSD1306 128x64 Pixels IIC 3.3V 5V White Character DisplayAZDelivery MCP23017 16-bit Bidirectional...
Understanding Weird CPUNow that I have spent some time reviewing other CPU project (it is good that I am not the only mad person out there!), I do find it hard to follow their concepts.So I will try and breakdown my schematic (divide and conquer!).Before...
Before I get into the circuits, I should talk about logic levels. In most transistor-based logic circuits, Boolean 0 and 1 are conveyed with high and low voltage levels, such as nominal 0 V and +5 V in TTL. This convention works fine...
In the previous post, I looked at ways to implement AND, OR and buffers with relays. But a full logic family requires the ability to invert a value. With a NC relay this is trivial: When A is zero, Q is 1. When current is applied to A, the...