leonardo46
Italy
Asked
Resolved by ptp!
I'm doing some experimentation sending a serial message ( 115200 baud rate) to ezbv4. The project sends a packet of 10 bytes every 100 mS.
The packet is not always being sent every 100 mS, but very often it is not sent, as you can see in this oscillogram.
(each pulse you see is the 10 byte packet) . The're correctly spaced by 100 mS , but many are missing.
C
Can somebody explain what's going on ??
Related Hardware EZ-B v4
:a
sendserial(d0,115200,0x KK, .......)
sleep(100)
sendserial (d0,115200,0xYY.......)
sleep(100)
goto (a)
the scope shows only a few seconds
I recall you asked a similar question sometime ago (2016/Jun):
https://synthiam.com/Community/Questions/How-Fast-Are-Scripts-5233/comments
Please read my post #6
Code:
Is this your exact script? The second sendserial command has a space between sendserial and the open parentheses....
get a logic analyzer or use an arduino to better understand what transmitting you’re sending, and what’s not transmitting. Mainly cause ezscript doesn’t handle binary data in strings very well. So that’s why the hardware uart or JavaScript version of sendserial should be used. Ezscript is really only included in ARC for backward compatibility
found this arduino logic analyzer if you have one lying around: https://create.arduino.cc/projecthub/vincenzo-g/diy-logic-analyzer-f61ee5
also, the software sendserial is a bit bang. Some client serial devices may require higher timing accuracy. In that case, use the hardware uart on the ezb v4
lastly, because you’re sending binary data, the hardware uart commands are best. If you wish to continue using sendserial, then use JavaScript because it will send binary data better. Ezscript isn’t great for that stuff...
here is the actual code:
alfa.EZB
@PTP . The script should send short pulses , each lasting about 800 uS ( 10 bytes at 155200 bauds ) .
This should happen every 100 mS, but the scope shows that many of them are skipped.
You also refer to a post of mine in 2016 when i, a newbie of ezb, tried to use ezb's analog ports to make a feedback system, that couldn't work, because of the delay caused by ezb itself. You and others explained that ezb isn't a real time system. So, for that purpose i used a local PIC MCU .
@DJ. sorry, Dj. I couldn't send the code before. it's up here.
I'haven't arduino or a logic analyzer. But my 100 Mhz Tektronix digital sampling oscilloscope shows with no doubt that many pulses are missing.
Note that the software uart at pin D0 outputs a perfect sequence of 10 bytes corresponding exactly to the script , but simply they aren't always sent every 100 mS as required by the script.
You can't expect 10 bytes each 100 ms !
What I wrote in 2016 is still true today. Please read again, the thread and the multiple posts, and let me know why you think this problem is not related.
I have read previous posts. Here the problem is different.
The 10 bytes sent at pin D0, at 115200 bauds, are perfect. The problem is the repetition every 100 mS. I could accept some error such as 70 or 130 mS or more, instead of 100 mS,, but it often doesn't send anything !... why ?
Code:
After try this one (verbatim):
Code:
Please post your findings
I don't want to introduce another "variable" (i.e. javascript vs EZ-Script speed) to the reported problem.
In 2016 I've explained the issue, Leonardo is still not understanding the issue, so I'm doing baby steps.
Test asked by PTP done.
Even sending the packets every 2000 mS, many packets are not sent !... Packets themselves are correct, , but they don't repeat well, some are skipped, no matter what is the repetion rate (2000,1000,500,100, etc.) . If someone had an oscilloscope , he might see with his eyes what happens.
I think it depends on the long time required by the ezb script to execute the repetition. For this now java is recommended by DJ.
DJ says "ezb isn't good for this stuff". java script should be better.
You wrote:
I only asked 2 simple questions
1) how many packets, did you get 16 packets ? Yes / NO
2) The timings between the packets ?
So before adding more variables Uart vs SoftwareSerial, or EZ-Script vs Javascript, I want you to understand the problem without missing steps (Wrong conclusion / Facts)
I couldn't see the pulses . They are too narrow to be detectable in a time interval of 2x16 =32 seconds ! I only saw some ones.
So I used, for the 2000 mS script , simply a LED, and no pulse was lost. Timing between pulses and inside the packets was correct.
For the 100 mS script i used the oscilloscope, and 8-9 pulses were always lost, in a random way, as i had seen in previous tests.
The spacing between them was variable in a random way, around 100 mS, and, inside the bytes, timing was random as well.
My question is solved . Thanks everybody. PTP solved.
if you want to provide details of the thing you’re trying to do, that would be easiest for us to help
i know your opinion about that (not enough info about protocol ,etc.). A hopeless work. However i'm going on.
I saw that your plug-in sends all together, many ( 16x10-byte) messages, for 16 servos. Perhaps too many.
I'm trying to send single messages, for a single servo, to see what happens.
I need some tool to send perfect messages, and realized that sendserial isn't good for that.
What was used in your plug-in? what can I use ?
As documented in the manual of the UB Tech servos plugin, the Send Serial (software serial) should only be used on IoTiny and never on an EZ-B v4. I recommend reading the manual for the UB tech servos in entirety.