[Gene] has a project that writes a lot of settings to a PIC microcontroller’s Flash memory. Flash has limited read/erase cycles, and although the obvious problem can be mitigated with error correction codes, it’s a good idea to figure out how Flash fails before picking a certain ECC. This now became a problem of banging on PICs until they puked, and mapping out the failure pattern of the Flash memory in these chips.
The chip on the chopping block for this experiment was a PIC32MX150, with 128K of NOR Flash and 3K of extra Flash for a bootloader. There’s hardware support for erasing all the Flash, erasing one page, programming one row, and programming one word. Because [Gene] expected one bit to work after it had failed and vice versa, the testing protocol used RAM buffers to compare the last state and new state for each bit tested in the Flash. 2K of RAM was tested at a time, with a total of 16K of Flash testable. The code basically cycles through a loop that erases all the pages (should set all bits to ‘1’), read the pages to check if all bits were ‘1’, writes ‘0’ to all pages, and reads pages to check if all bits were ‘0’. The output of the test was a 4.6 GB text file that looked something like this:
Continue reading “Flash Memory Endurance Testing”
The Hackaday Prize party wasn’t just about the five finalists; actually, there were more THP entries in attendance – All Yarns Are Beautiful, OpenExposer, M.A.R.S., a 3D scanner, and a few more that I’m forgetting – than actual finalists. In addition, a number of people brought projects that had never seen the light of day, like [Ralf] and [Pamungkas]’ Phoenard.
Phoenard is a Kickstarter project the guys launched at the prize party, something they could attend as a little side trip after manning the ‘maker’ part of the Atmel booth at Electronica. They’ve come up with a tiny handheld device that can only be described as a ‘gadget’. It has a touchscreen, a battery, an MegaAVR, a few connectors, and not much else. What makes this project cool is how they’re running their applications. A bootloader sits on the AVR, but all the applications – everything from a GSM phone to an MP3 player – lives on a microSD card.
The Phoenard guys have come up with a few expansion modules for Bluetooth LE, GSM, GPS, and all the usual cool modules. Plugging one of these modules into the back of the device adds capability, and if that isn’t enough, there’s an old 30-pin iPhone connector on the bottom ready to accept a prototyping board.
Video of these guys below.
Continue reading “Phoenard, A Prototyping Gadget”
There have been countless projects to make custom photo flash trigger circuits. Usually the circuits react to sound, triggering the camera flash at the moment a certain sound is triggered. That type of trigger can be used to detect the popping of a balloon or shattering of glass. Other triggers detect motion, like a projectile crossing a laser beam for example. [Udo’s] friend had a fun idea to take photos of water balloons popping. Unfortunately neither of those trigger methods would be well suited for this situation. That’s when [Udo] had to get creative.
[Udo] built a unique trigger circuit that uses the water inside the balloon as the trigger. The core component of the circuit is an Arduino. One of the Arduino’s analog pins is configured to enable the internal pull-up resistor. If nothing else is connected to the pin, the Arduino will read 5 volts there. The pin is connected to a needle on the end of a stick. There is a second needle on the same stick, just a short distance away from the first. When these needles pierce the balloon’s skin, the water inside allows for a brief moment of conductivity between the two pins. The voltage on the analog pin then drops slightly, and the Arduino can detect that the balloon has popped.
[Udo] already had a flash controller circuit. He was able to trigger it with the Arduino by simply trying the flash controller’s trigger pin to one of the Arduino’s pins. If the Arduino pulls the pin to ground, it closes the switch on the flash controller and the flash is triggered. Both circuits must share a common ground in order for this to work.
All of the code for [Udo’s] project is freely available. With such spectacular photographs, it’s only a matter of time before we see more of these floating around.
The Bus Pirate is a cheap, simple, Swiss army knife of electronic prototyping, capable of programming FPGAs, and writing to Flash memory. The uISP is possibly the most minimal way of programming Atmel chips over USB, using less than $5 in components. Although the uISP is using a slower chip and bit-banging the USB protocol, it turns out it’s actually faster when operating as a programmer for SPI Flash memories.
Most of [Necromancer]’s work involves flashing routers and the like, and he found the Bus Pirate was far too slow for his liking – he was spending the better part of four minutes to write a 2 MiB SPI Flash. Figuring he couldn’t do much worse, he wrote two firmwares for the uISP to put some data on a Flash chip, one a serial programmer, the other a much more optimized version.
Although the ATMega in the uISP is running at about half the speed as the PIC in the Bus Pirate, [Necromancer] found the optimized firmware takes nearly half the time to write to an 8 MiB Flash chip than the Bus Pirate.
It’s an impressive accomplishment, considering the Bus Pirate has a dedicated USB to serial chip, the uISP is bitbanging its USB connection, and the BP is running with a much faster clock. [Necro] thinks the problem with the Bus Pirate is the fact the bandwidth is capped to 115200 bps, or a maximum throughput of 14 kiB/s. Getting rid of this handicap and optimizing the delay loop makes the cheaper device faster.
No, that’s not a Playstation Vita up there, it’s a “Yinlips YDPG18A” portable game system. [Ian] found that his Yinlips was lacking in the flash memory department, so he fired up his soldering iron. The Yinlips is based on an Allwinner Sunxi series processor, and uses a standard TSOP48 footprint flash. There is some standardization in flash pin out and packages, so [Ian] picked up the largest pin compatible chips he could find – a pair of 256 gigabit (32 gigabyte) chips from Micron. Desoldering the existing flash proved to be a bit of an adventure as the flash was glued down. [Ian] also didn’t have his hot air gun handy, making things even more interesting. Careful work with a razor blade broke the glue bond.
It turns out that the soldering was the easy part. All flash chips have geometry, die count, page size, block count, sector size, etc. The geometry is similar to the geometry in a hard drive. In fact, just like in modern hard drives, a system will read some basic information before accessing the full storage array. In the case of NAND flash, the processor can access the first page of memory, and query the flash for its part number. Once the part number is known, the geometry can be determined via a lookup table. [Ian] checked the NAND table on github, so he knew going in that his flash chips were not supported. Due to the complexities of booting Allwinner processors into Linux or Android, the table and the NAND driver that uses it exist in several places. The bootloader’s axf file, U-Boot, and several flash application binaries sent from the PC based LiveSuit flash app all required modification. Most of these files were packed into a single flash image. [Ian] used imgrepacker to unpack the image, then opened the hex files. The fact that he knew what the original flash parameter tables looked like was key. He searched for an existing Micron flash table entry, and replaced the parameters with those of his new chips.
With all the files modified, [Ian] re-packed his flash image and sent it over. The Yinlips rewarded his hard work by continually resetting in a bootloop. [Ian] wasn’t going to give up though. He wired into the boot console, and discovered that a CRC check failure on one of his modified files was causing the reset. He then disassembled binary issuing the reset. Changing the return value of the CRC to always pass fixed the issue. [Ian’s] now has a collagen infused Yinlips with 58GB of internal storage. Pretty good for a device that only started with 2GB.
[Petri]’s first computer was the venerable Commodore VIC-20, predecessor to the Commodore 64. With only 5kB of RAM, a very simple graphics chip, and BASIC, it’s a bare-bones system that’s perfect for a 7-year-old future programmer. [Petri] was trying to figure out something to do with this old computer, and realized the simple schematic would allow him to recreate those classic VIC-20 cartridges using modern hardware.
This project began by cracking open a few game cartridges to see what was inside. They’re very simple devices, consisting of a decoupling cap and a ROM chip wired directly to the data and address busses. [Petri] desoldered the ROM and replaced it with a ribbon cable that would give him a clean breadboard to VIC-20 expansion port interface.
Instead of finding a contemporary EEPROM chip to program, [Petri] decided on using a Flash chip. The original cartridge had a 16kB ROM chip, but the smallest parallel Flash chip he could find was 256k. No problem, then; just ignore a few address lines and everything worked out great.
After getting the VIC-20 reading the breadboarded Flash chip, [Petri] started work on a circuit that would program his Flash chip while still attached to the expansion port. With a few buffer chips and an ATMega32a loaded up with Arduino, he’s able to program the Flash chip and turn it over to the VIC-20.
A simple test that toggled the color of the screen as quickly as possible was all that was needed to test the new circuit. Now, [Petri] can finally start on programming some games for his first love.
Continue reading “Flash Game Cartridge For The VIC-20″
[Toby] has an Elinchrom EL-Skyport, which is a wireless flash trigger. He decided to see if he could trigger it using an Arduino, and came up with a nice proof of concept. This little device was not meant to be user serviceable, as can be seen in what [Toby] uncovered while taking it apart. But once he had it disassembled, he cataloged everything inside, and then he awesomely went to the trouble of drawing up a schematic. With that knowledge, he began reverse engineering the SPI protocol used, which almost deserves an article by itself.
It was a long road to get there, but in the end [Toby] built a prototype Arduino shield that houses an nRF24L01+ module. These are very cheap to pick up on eBay. He gives us the details on hooking up the module, though he had to go through extra hoops since he was using the Arduino Leonardo. Still, once you’re up and running, you can make use of one of the existing libraries specifically for this module.
Thanks to his effort, the rest of us have one more device to hack on. Thanks [Toby]!
Continue reading “Elinchrom EL-Skyport Triggered by Arduino”