Everything you always wanted to know about Eclipse, Embedded Systems Programming, Software and Tools, or any topics of this blog, but where afraid to ask, then this page is for you.
Post a comment, and you might get an answer, either from myself or from the readers of this blog. Otherwise: the answer is always ‘42‘ 😉
For feature requests or bug reports on the McuOnEclipse project end Processor Expert components, you should use the GitHub issue tracking system:
- McuOnEclipse Processor Expert components: https://github.com/ErichStyger/McuOnEclipse_PEx/issues
- McuOneEclipse example projects: https://github.com/ErichStyger/mcuoneclipse/issues
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Hi Erich! great work on his blog ! I’ll use some of your code inside my project ! Quick question about the freeRTOS PE component. I seem to get lost with the priority scheme of freeRTOS, interrupt and your implementation of the freeRTOS component.
I want to be sure of one thing : IDLE task is assigned priotity 0, I guess it’S the lowest priority, the priority we give in FRTOS1_xTaskCreate() (PE component) should be related to priority number of the free RTOS right ? not the priority of the interrupt.. which are inverted right ?
lets says i create 2 tasks with your component :
FRTOS1_xTaskCreate(tsk1, “Task1”, configMINIMAL_STACK_SIZE, &globalhost, 1, NULL);
FRTOS1_xTaskCreate(tsk2, “Task2”, configMINIMAL_STACK_SIZE, &globalhost, 2, NULL);
Task2 priority will be greater than Task1 ?
sincerely.
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Hi Etienne,
the FreeRTOS component is using the normal FreeRTOS priority scheme (nothing different). If you are new to FreeRTOS and the ARM Cortex interrupts, then I recommend that you have a read at the multipart tutorial starting at https://mcuoneclipse.com/2016/08/14/arm-cortex-m-interrupts-and-freertos-part-1/.
Keep in mind that FreeRTOS priorities start with zero as the lowest priority, while the ARM Cortex priorities have zero as the highest urgency level.
So yes, 0 (or tskIDLE_PRIORITY) is the FreeRTOS priority for the IDLE task. The RTOS itself runs with its interrupts (SysTick, PendSV and PendSvReq) at the lowest interrupt priority (15 for 4 priority bits).
And yes, for your example, the Task2 his higher urgency than Task1 and this one has higher urgency than the IDLE task.
I hope this helps,
Erich
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Hello, Erich! I really ensjoy your blog!
I have a question about mbed, especially openSDA.
I build a board based on FRDM-KL43Z.
My trouble is my boards are doesn’t work in my PC. I think absent of bootloader is main problem. Can you teach me how install a new bootloader in a board? There is none-S/W in my board.
Here is my board symptom.
1. Power LED is working
2. MCU USB port ack as USB serial. But it cannot use as storage.
3. openSDA USB unack.
sincerely,
Soo-Chang
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Hi Soo-Chang,
have a read at https://mcuoneclipse.com/2014/11/01/illustrated-step-by-step-instructions-updating-the-freescale-freedom-board-firmware/ how to update the bootloader/application.
If you are using Windows 8 or 10, then have a read at https://mcuoneclipse.com/2016/08/01/bricking_and_recovering_opensda_boards_in_windows_8_and_10/ too.
I hope this helps,
Erich
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Hello again.
I tried your guide. But it is different situation.
My board flash is empty. So it doesen’t work as a writable device.
Anyway I really appreciate of your advice again.
sincerely Soo-Chang
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Your openSDA/K20 is programmed, right? It does not matter if your KL43Z is empty or not: the K20 will programm it, no matter what.
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Actually, I’m not sure about that. I made my own PCB based on KL43Z. I used new K20. I think OpenSDA/K20 is not programmed as well. I don’t have any S/W in my board.
I think the only way to install the bootloader is using jtag.
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Ah, I see, I thought you are talking about the FRDM-KL43Z. So yes, if you have a board with a new K20DX128 chip, you need to program it first with the bootloader. E.g. in a way described in https://mcuoneclipse.com/2016/06/26/how-to-recover-the-opensda-v2-x-bootloader/
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Thank you, Erich!
I will follow your advice. Thankyou again!
I will update my data later.
P.S. Happy new year!
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Hi…in my case my boards are doesn’t work in my PC. I think absent of bootloader is main problem. Can you teach me how install a new bootloader in a board? There is none-S/W in my board.
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That depends on the board. Which board are you using? Otherwise have a read at https://mcuoneclipse.com/2014/11/01/illustrated-step-by-step-instructions-updating-the-freescale-freedom-board-firmware/
I hope this helps,
Erich
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Hi Erich,
I just noticed that NXP has a Low Voltage Hbridge PE component (LVHBridge) , and also a medium voltage Hbridge (MVHBridge) component that can be downloaded and work on processors like the K20’s with Processor Expert. Have you seen these before and do you have any experience with them?
I found it because I want to make a stepper motor driver (microstepping) using discrete components on the theory that it could be better/cheaper than using a microstepping chip- these components look like the easy way to do so.
Brynn
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I have no experience with these components.
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Hi Erich,
I am working on a project where I send short text messages between a K64F and an android tablet. I want the K64F to be a host and the tablet to be a device. How do I do this. Do I need an OTG cable.
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Hi Eli,
the means that the K64F needs to be in host mode. If you are using the FRDM-K64F board, then this is not supported out of the box. Basically you need to supply 5V from the board to the tablet. See https://mcuoneclipse.com/2012/10/15/usb-host-mode-hack-for-the-freedom-kl25z-board/ and https://mcuoneclipse.com/2013/03/02/usb-msd-host-for-the-freedom-board/. The bigger thing is that you need a USB CDC host implementation running on the K64F. I had this on my ‘wish list’ for a very long time, but never got to the point to have the USB stack working that way. You might need to check the latest NXP MCUXpresso SDK if it supports what you need?
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Hi Erich
I am trying to modify your example using the Adafruit SPI friend. I want to use the Freedom K64F instead of the Tiny20.
For the Adafruit SPI you use 5 IO lines. I want to use the Adafruit UART friend, no interrupt and the CS tied to GND. This will use up only 2 IO lines.
Will this work?
Thanks
Eli
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Using the K64F instead the K20 should be pretty straight forward. But there is no CS line on the UART friend (https://www.adafruit.com/product/2479)?
Keep in mind that for the UART friend you have to use UART hardware flow control, and not every UART peripheral might support that. From that perspective, the SPI BLE Friend is much easier to use imho.
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Hi Erich,
Great website ! I found the site not too long ago ! You seem like a person who loves these works and want to teach others as well!
I have been struggling to learn embedded electronics but what I have discovered missing is a complete guideline from beginner to expert. If you could write an article on where to start and how to grow from there would benefit many beginners like me I believe.
Thanks
Mark
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Hi Mark,
thank you for that feedback and suggestion. My suggestions would be to look first for some of the older articles (as they are more beginner like). And what would you define as tha ‘beginners knowledge’ to build upon?
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First, thanks for the quick response. I would say a beginners knowledge is basic knowledge of programming in C, some familiarity with electronic components and someone with enough knowledge to play around with arduino or similar platform. For example, right now I find programming in arduino or in mbed online compiler fairly easy as they hide many details. Also there are a lot of tutorial for them available online as well. But when I dive under the hood,I don’t know where to begin with.
Mark
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Hi Mark,
maybe have a look at tutorials like these:
https://mcuoneclipse.com/2016/03/13/tutorial-blinky-with-the-frdm-kl27z-and-kinetis-sdk-v2/
https://mcuoneclipse.com/2016/05/20/tutorial-blinky-with-nxp-kinetis-sdk-v2-0-and-processor-expert/
https://mcuoneclipse.com/2017/05/13/mcuxpresso-ide-blinky-the-nxp-lpc800-dip-board/
Erich
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Perfect ! Thanks a lot for taking your time to find the links for me!
Have a great day !
Mark
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Hi Erich,
So I was trying to do the DIY USB joystick but I keep getting this error: “Description Resource Path Location Type
Generator: FAILURE: at line 10: Property not found: “TxBuffer” (file: Drivers\Common\FSL_USB_HID_Joystick_DeviceSettings.Inc) FRDM-KL25Z_USB_HID_Joystick HIDJ1 Processor Expert Problem”
Can you help me please?
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Hi,
I suggest that you post that question directly to the article you are using? Are you using my project from GitHub (which one)?
But it seems to me that you did not assign a ring buffer to the USB component?
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I was trying to comment on that post but it says sorry can’t post :(. It’s the project from Github and the tutorial is on this site too. https://mcuoneclipse.com/2017/06/04/diy-usb-hid-joystick-device-and-game-controller/
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It let me comment on the tutorial now :).
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Hi again
I have an android tablet talking to a K64F using the Adafruit LE uart. However it will not send more that 20 bytes at a time.Is there a way to increase this limit.
Thanks
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You have to implement message fragmentation (sending larger chunk of data with multiple messages). The BLE protocol is optimized for low power and small amount of data, you cannot send more than this 20 bytes in a a single message.
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Hi Eric,
Great work. Really appreciate your insights. Had a question. Is it possible to shutdown a cortex m4? I understand the CPU can be configured to go in Stop Mode or Sleep Mode, but is it possible to to initiate a shutdown from software? I don’t think it is possible as I cannot find any register set that lets me perform such an action, but wanted to run it by you as well
Thanks again
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apologies for misspelling your name. I meant to type Erich
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No worries, both variants work very well 🙂
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You can reset any M3/M4/M7 using the approach described in https://mcuoneclipse.com/2015/07/01/how-to-reset-an-arm-cortex-m-with-software/. But this will be a reset/restart.
If you want to do a ‘shutdown’ as on the PC then could either go into deep sleep mode or do a reset and right after that go into deep sleep.
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yep. that’s what I had in mind as well. Thanks soo much. Once again, a great website and great resources.
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Hello Erich,
First of all I would like to thank you for the awesome work and for the effort you have put into these tutorials. I have the following question. I ordered the product FRDM-K64F-AGM01, which consists of a shield and a development board. From the pictures at NXP site, I infered that the sensor shield board would be removable and that I could use the FRDM-K64F standalone. The problem is I can’t remove the shield (if I apply more pressure, I am scared that I will break the board). Do you know if it is supposed to not be removed?
Thanks in advance,
Panagiotis
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It should be removable. I don’t have that kit, but from the pictures it really should be removable. You should be able to tell this with having a close look at the headers: ther must be a black (high) black row of female headers on the FRDM-K64F board, with a row of male pin headers on the AGM01 board. Try to lift the board carefully on one end, then on the ohter, and so on.
I hope this helps,
Erich
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