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by bitbank
Thu Aug 24, 2017 3:14 pm
Forum: Beginners
Topic: Tiny LCD on pi
Replies: 5
Views: 1192

Re: Tiny LCD on pi

It looks like you've got the I2C version of that display (there are also SPI versions). You should connect it to your Pi like this: Display :: RPi header VCC -> 3.3V (header pin 1) GND -> GND (header pin 6) SCL -> SCL (header pin 5) SDA -> SDA (header pin 3) You can test that it's working with my C ...
by bitbank
Tue Aug 22, 2017 3:45 pm
Forum: Camera board
Topic: faster raw (bayer) procesing
Replies: 8
Views: 1621

Re: faster raw (bayer) procesing

An important part of getting good performance out of modern CPUs (ARM + x86) is to make efficient use of the write buffer. This is a bit of hardware connecting the write circuitry of the CPU to the memory. Since memory is much slower than instruction execution, a 4-deep cache (write buffer) is added...
by bitbank
Fri Aug 18, 2017 3:42 pm
Forum: Camera board
Topic: faster raw (bayer) procesing
Replies: 8
Views: 1621

Re: faster raw (bayer) procesing

Manipulating a single frame of raw bayer into a full res image should take on the order of milliseconds, not seconds. I'm not familiar with numpy, but if you want to get some speed, use a native language (e.g. C). If you post the algorithm in an understandable form, I can convert it into efficient C...
by bitbank
Fri Aug 11, 2017 12:19 pm
Forum: Graphics, sound and multimedia
Topic: Multiple TFTs with RGB
Replies: 8
Views: 1464

Re: Multiple TFTs with RGB

Alt2 mode means using DPI interface. There is only one framebuffer, so all your displays will show the same content and must be the same type - because there is only one configuration for DPI too. I thought if I feed each display with pixel clocks having different phases, I could get different fram...
by bitbank
Thu Aug 10, 2017 10:41 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Dual TFT displays?
Replies: 2
Views: 966

Re: Dual TFT displays?

You can easily connect 2 or more SPI-connected LCD screens simultaneously. Depending on the resolution/speed and content you plan to display. Search ebay for "ili9341" and you'll see a bunch of 240x320 displays for under $10 each. On Raspberry Pi's without much effort, you can get 30fps refresh on t...
by bitbank
Thu Aug 10, 2017 4:15 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI speeds
Replies: 5
Views: 2604

Re: SPI speeds

30 FPS on a ili9341 sounds awesome. That would do nice smooth animation. I have been using the 2.4" ili9341 screens as they r great for small robotics with limited space. I have been using spidev functions setting max baud rate of 64mhz. As you say this might not be the finial speed to writes to th...
by bitbank
Wed Aug 09, 2017 12:43 pm
Forum: Camera board
Topic: Cheap RC airplane with "outboard" Pi Zero and camera
Replies: 45
Views: 20590

Re: Cheap RC airplane with "outboard" Pi Zero and camera

Very creative and thanks for sharing the link to the plane. It would be fun to also hack the remote control receiver to control it from the RPi0. Perhaps even create an automated flight path using a GPS+compass. Lots of possibilities for fun projects. How about adding a BME280 to measure the temp/hu...
by bitbank
Wed Aug 09, 2017 12:20 pm
Forum: Italiano
Topic: Retrogaming con Raspbian
Replies: 2
Views: 713

Re: Retrogaming con Raspbian

Salve,
Chiaro è possibile. Retropie è una modificazione di Raspian con molto software pre-installato. Può utilizzare qualsiasi software senza Retropie con Raspian/Debian/Ubuntu/baremetal. Il mio emulatore di giochi (SmartGear) è un exe indipendente:

https://www.youtube.com/watch?v=PJp1Ml-ZaD4
by bitbank
Wed Aug 09, 2017 11:30 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI speeds
Replies: 5
Views: 2604

Re: SPI speeds

Yes, you interpreted it correctly. The actual data throughput depends on how you access SPI. If you use WiringPi or the Linux spidev driver (same thing), you'll get a lower effective speed because there is an inherent delay in passing the data from userland to the kernel driver. If you use the PIGPI...
by bitbank
Wed Aug 09, 2017 11:19 am
Forum: Graphics, sound and multimedia
Topic: Multiple TFTs with RGB
Replies: 8
Views: 1464

Re: Multiple TFTs with RGB

A few questions: 1) What size/resolution displays? 2) What will you be displaying on them? 3) What refresh rate do you need? Since you haven't specified, the simplest way to get 3 LCD displays is to use 4-wire SPI displays. They won't be fast and you won't necessarily get standard Linux drawing feat...
by bitbank
Mon Aug 07, 2017 2:30 am
Forum: General discussion
Topic: Controll mouse and keyboard via bluetooth Rpi3
Replies: 5
Views: 807

Re: Controll mouse and keyboard via bluetooth Rpi3

Bluetooth supports many protocols and RFCOMM is just one of them. It doesn't make sense for a phone to advertise a service over RFCOMM. You can write an app on the phone which accepts socket connections via RFCOMM service.
by bitbank
Sun Aug 06, 2017 5:36 pm
Forum: General discussion
Topic: Cycling Sensors for Cycling Computer
Replies: 19
Views: 4432

Re: Cycling Sensors for Cycling Computer

Something like this would work: http://www.ebay.com/itm/IR-Optical-Limit-Switch-Endstop-Tachometer-Speed-Sensor-Module-for-Arduino-ESP32/292127305828?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 You can look at my pi_car project for the code to talk to it. You set up a GPIO interrupt a...
by bitbank
Sun Aug 06, 2017 1:31 pm
Forum: Automation, sensing and robotics
Topic: pi_car a bluetooth gamepad+RPi0W controlled car
Replies: 7
Views: 1375

Re: pi_car a bluetooth gamepad+RPi0W controlled car

Lots of cool things you can add/do with this base you have. Have you though about motion processing gyro, accelerometer, compass to detect direction of travel to be able to navigate maybe even dead reckoning. You can add computer vision very easy these days. U can old school it and use a PiCam and ...
by bitbank
Sun Aug 06, 2017 1:28 pm
Forum: General discussion
Topic: Controll mouse and keyboard via bluetooth Rpi3
Replies: 5
Views: 807

Re: Controll mouse and keyboard via bluetooth Rpi3

You can see what I did in my Zeemouse project for how to do that. X11 has an API which allows you to inject key and mouse events. My project uses a bluetooth gamepad to drive the mouse/keyboard using RFCOMM to the custom protocol of the gamepad. You can use most of the same code to do what you need...
by bitbank
Fri Aug 04, 2017 4:13 pm
Forum: Automation, sensing and robotics
Topic: pi_car a bluetooth gamepad+RPi0W controlled car
Replies: 7
Views: 1375

Re: pi_car a bluetooth gamepad+RPi0W controlled car

Imperf3kt wrote:
Thu Aug 03, 2017 10:29 pm
Maybe some LED head/tail lights?
Aesthetics are definitely in short supply with this project considering that I have to use masking tape to hold the sensors in place. I appreciate your suggestion. I'm looking for ideas for functionality.
by bitbank
Fri Aug 04, 2017 3:12 pm
Forum: Português
Topic: Help!!!!
Replies: 1
Views: 663

Re: Help!!!!

GPIO deve ser ativado já. Para confirmar tecla:

ls /sys/class/gpio

Se tudo está certo, vai ver:
export gpiochip0 unexport

Se não, executa:
sudo raspi-config
e habilita o GPIO
by bitbank
Fri Aug 04, 2017 3:13 am
Forum: Off topic discussion
Topic: Asus Tinker board
Replies: 155
Views: 16026

Re: Asus Tinker board

I cannot imagine Rasbnian working on this thing out of the box. The Pi relies on the GPU and the secret binary blob to get it booted. I'm pretty sure this machine does not have the same GPU or even use the same boot method. If you're using the Tinkerboard to run Android with a touchscreen, it seems...
by bitbank
Thu Aug 03, 2017 10:02 pm
Forum: Automation, sensing and robotics
Topic: pi_car a bluetooth gamepad+RPi0W controlled car
Replies: 7
Views: 1375

pi_car a bluetooth gamepad+RPi0W controlled car

I'm still on my continuing quest to learn about every RPi sensor/accessory and release improved software for it. My current project is a 4WD RPi0W controlled car. The project will progress in stages. The first stage (completed) is to control the car (speed/direction) using a bluetooth wireless gamep...
by bitbank
Thu Aug 03, 2017 5:23 pm
Forum: C/C++
Topic: [pigpio] Bad I2C Bus
Replies: 6
Views: 1665

Re: [pigpio] Bad I2C Bus

I2C bus 0 is not exposed on the header, it's I2C bus 1. Change the first parameter to a 1 and make sure that it's enabled by doing "ls /dev" and make sure it's visible in the list. If not, run raspi-config and enable it.
by bitbank
Wed Aug 02, 2017 5:11 pm
Forum: Other programming languages
Topic: Register allocation (assembly language)
Replies: 32
Views: 6535

Re: Register allocation (assembly language)

Part of the 'art' of writing assembly language is making those choices. I choose a register for each variable in my algorithm starting with r0-r3. Hmm, but the first BL to, say, a libc function can potentionally stomp on all of R0-R3, in which case wouldn't it have been better to allocate any varia...
by bitbank
Wed Aug 02, 2017 5:02 pm
Forum: Other programming languages
Topic: Register allocation (assembly language)
Replies: 32
Views: 6535

Re: Register allocation (assembly language)

Part of the 'art' of writing assembly language is making those choices. I choose a register for each variable in my algorithm starting with r0-r3. It's just the way you have to work. If you need more variables than can fit in registers, then you need to manage working with the stack or storing them ...
by bitbank
Wed Aug 02, 2017 12:32 pm
Forum: General discussion
Topic: Supply Chain
Replies: 11
Views: 1690

Re: Supply Chain

We have considered alternative single board computers, but there is nothing on the market that matches the price/performance ratio. HELP! The IoT market is constantly in flux and this statement is no longer true. I don't bring this up to take away anything from the fine work the RPF is doing, but t...
by bitbank
Wed Aug 02, 2017 12:15 pm
Forum: General discussion
Topic: Controll mouse and keyboard via bluetooth Rpi3
Replies: 5
Views: 807

Re: Controll mouse and keyboard via bluetooth Rpi3

You can see what I did in my Zeemouse project for how to do that. X11 has an API which allows you to inject key and mouse events. My project uses a bluetooth gamepad to drive the mouse/keyboard using RFCOMM to the custom protocol of the gamepad. You can use most of the same code to do what you need:...
by bitbank
Tue Aug 01, 2017 3:29 pm
Forum: Gaming
Topic: *NEW* - ILI9341(240x320 LCD) Library designed for gaming
Replies: 7
Views: 4138

Re: *NEW* - ILI9341(240x320 LCD) Library designed for gaming

I'm not ready to share the whole source code yet. The key parts are to use a renderer and streaming texture. Code snipped below has error checking removed for brevity: renderer = SDL_CreateRenderer(sdlwindow, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC); texture = SDL_CreateTexture(rend...
by bitbank
Mon Jul 31, 2017 5:25 pm
Forum: Troubleshooting
Topic: SSD1306 problems on PI Zero
Replies: 7
Views: 1968

Re: SSD1306 problems on PI Zero

Hi, i was trying pretty hard to get the ssd1306 oled display working on my raspberry, but i can't really figure it out, because there seems to be a problem with the actual bus communication that i'm unable to debug unfortunately. The display board is that one: http://www.ebay.de/itm/Blue-0-96-IIC-I...

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