Most recent activity
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Thr 2017.06.01
From #14
Thank you @allObjects for the datasheets and detailed analysis.From #21
@trusktr after consideration of your project requirements, the suggestion that Gordon made of using a USB power pack makes more sense for the demo, my suggestion for the power adaptor (I use a Kindle charger) should you have one lying around or for long term power on requirementsFrom #19
Just to confirm, this is to the 3.3v pin (which the schematic calls "3.3v output"), NOT the VUSB pin?
As @trusktr had the same question, would @Gordon please expound on the following to add clarification for us all:
It is given that: (links found in #2 above)
- The schematic at github shows that there is a VBUS [ J2-2 ] and a VUSB
- The regulator shows an input of 5v but isn't clear on it's origin (after Fuse F1 perhaps)
- EspruinoWiFi documentation explains that the 3.3v pin [ J2-3 ] is an output
- There is a stern warning not to connect VBUS [ J2-2 ] when the micro USB connector is attached
Q1: Was this distinction VBUS vs VUSB made for schematic software reasons and not a typo?
Q2: What/Where is the connector showing VUSB/DM/DP or is this the input to the WiFi module?
Q3: Under the assumption the micro USB connector is feeding the power, is it true that VBUS [ J2-2 ] is available as an output and that it is electrically connected to the input (after Fuse F1 perhaps) of the regulator as 5v (the source a USB port supplies), and therefore also supplying 3.3v as VDD [ J2-3 ] as an output?
Q4: Under the assumption that supplemental power from a 3.3v battery is supplied, and that no micro USB connector is attached, that is could be applied as an input VDD at [ J2-3 ] bypassing the onboard regulator?
Note: This would mean there is no fuse protection and that input voltage would not be detectable at PA9/P30Q5: Similarly as above, upto 5v could be supplied by a regulated supply to VBUS [ J2-2 ], thus using the onboard voltage regulator, producing the 3.3v to the rest of the circuitry, and at VDD [ J2-3 ] as an output?
Thank you Gordon
- The schematic at github shows that there is a VBUS [ J2-2 ] and a VUSB
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Wed 2017.05.31
This code fiddle popped up in a separate forum that may provide a shortcut in program development time. https://benjaminbenben.com/espruino-pixels/ @benjaminbenben
from: (#11) http://forum.espruino.com/conversations/305442/#comment13656647
Would love to get an update on your project success @OwenBrotherwood
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@trusktr are you dead set on battery power at this time, e.g. are you really at the development stage and will be writing code for the near future? If so, I would consider @Gordon suggestion of a dedicated supply to avoid the hassles with battery use. You will be thankful, we know this based on experience. Have you considered using a cell phone charger? I run my Espruino projects using a leftover 5v 800ma cell phone charger with a micro USB plug on the end, which I plug into a micro USB receptacle whose pins fit nicely into the solderless breadboard. Mine has been running non-stop for three months now for just pennies to the all mighty power company. My 0.02 worth.
EDIT:
I make this suggestion as the picture above (#13) shows the battery with a rating of 600mAhr Running WiFi continuously, say 300ma, will only provide a max of two hours of use. Much less with other attached devices, and remember actual mileage will vary. . . . -
Mon 2017.05.15
"It'll be my first IoT board purchase, i'm new to all that."
It is good that you are asking the right questions and I'm sure you will be excited making the correct IoT choice. Supporting @Gordon with an Espruino brand IoT board purchase would be appreciated.
"and could operate on something for months on a 2000mAh cell"
You are correct @Thinkscape under certain conditions. I believe it was @Gordon that covered this in a post I am still trying to locate. I'll do my best to summarize until that link is found.
The idea is to run the device on a 1% duty cycle running at the 20ua drain 99% of the time. These devices consume around 50ma to wake up, 100ma at impulse for mild number crunching, 200ma during warp drive, and up to 500+ma using WiFi etc. The GPIO pins can source around 25ma but the total chip source is only around 100ma for all IO out meaning around five LEDs at 20ma each. As one can see, during excessive WiFi use, an external (wall-wort) power source is recommended to save on battery draw.
Still seeking that link,
RobinESP8266 - NodeMCU - led and ds1820 temperature example
http://www.espruino.com/Wireless+Temperature+Sensor
http://www.espruino.com/Tutorials
EDIT Mon 2017.05.15
Still searching for that post but did find the following:
@allObjects posted the chip GPIO data:
'maximum current from the espruino pins'
http://forum.espruino.com/conversations/280779/#comment12746768See p.59:
http://www.espruino.com/datasheets/STM32F401xD.pdf- Each GPIO pin can source or sink only 25ma
- Total max all pins is 120ma
- Each GPIO pin can source or sink only 25ma
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Does this provide some insight:
"Example code for the "Chirp" soil moisture sensor"http://forum.espruino.com/conversations/270246/#comment13634478
http://www.espruino.com/simple_data_logger
http://www.espruino.com/Tutorials -
Does this post provide some insight http://forum.espruino.com/comments/13622029/
Could you elaborate on how much of an 'exact distance' you are expecting to achieve?
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Thank you @allObjects for clearing that up. I liked your concise explanation within the pp detail on battery differences.
Did you mean 100..2100ma to be 2.1A and not 1.2 as indicated?
I was surprised to learn that my PC had a USB3 port along with the USB2 ports. The 500ma value has a bit of latitude when on a USB3 port. 900 big ones!
https://en.wikipedia.org/wiki/USB_3.0
"As with earlier versions of USB, USB 3.0 provides power at 5 volts nominal. The available current for low-power (one unit load) SuperSpeed devices is 150 mA, an increase from the 100 mA defined in USB 2.0. For high-power SuperSpeed devices, the limit is six unit loads or 900 mA (4.5 watts), almost twice USB 2.0's 500 mA"
For what it's worth, I've not had an issue, yet, . . . running WiFi over USB2/USB3, but I heed your warning. That said, I chose to power my little critters with an external supply, lest I suffer the wrath of extra electrons wanting to take an undesired path while I'm on a productive breadboard design streak.
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Sun 2017.05.14
Hello @Thinkscape,
Although I have no experience with the WiFi version;
I'll agree with you the documentation could be improved with this bit of detail. Do you currently have the WiFI board, or are you considering a purchase?
Have you checked out these resources:
http://www.espruino.com/WiFiNote the section in red, just below 'Pins not on connectors'
So, it appears that 3.3v could be supplied to pin J2-3 , Gnd to J2-1 , rather than and instead of powering via the micro USB
See EDIT below
This would mean of course, tack soldering your JST connector choice to the top of the header pins.
Schematic:
https://github.com/espruino/EspruinoBoard/blob/master/WiFi/pdf/espruino_wifi_sch.pdfNote: The schematic shows both VBUS and VUSB All text documents refer to VUSB Not sure if this was intentional, or just to differentiate between power in via the connector VBUS and that used to supply circuits on the board itself VUSB.
This detail should suffice in the meantime until another with actual hands-on experience can assist here.
Robin
EDIT:
From the bullet list just below 'Pinout'
"3.3 is a 3.3v output from the on-board Voltage regulator."
Although this pin is on the downside of the regulator, there isn't any reason schematically this couldn't be used as a supply pin. However, just now locating this comment, leaves me with a bit of doubt, as it is specified as an output pin. So, not sure if my suggestion to tack solder a connector here is prudent.
Maybe, J2-2 labeled VBUS (on schematic VUSB on diagram) could be used as long as the battery supply is above the voltage regulator input requirement.
"On-board 3.3v 250mA voltage regulator, accepts voltages from 3.5v to 5v"
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Would this tutorial (with modification) solve the BLE in range detection?
Fri 2017.06.02
Thank you @allObjects for the simple response on dual power.
As there appears that re-editing seems to plague this thread, [me included ;-) ] isn't there a missing 'not' or 'never' in the sentence 'This is the reason that . . . ' and a missing closing ')' found in (#24) ?
@Gordon thank you for the clearing that up. I missed (what the device did\was) the 'LM3671' reference in post #22 and your similar responses to those posed by my suggested clarification. I felt it made more sense to ask explicitly so as to tie in with the documentation that appeared to have missing detail. I'm sure that the topic re-visit will help @trusktr and assist @Thinkscape and others as it has me.
Maybe there is a simple way to show how to connect, which pins to connect to, using the three power input choices in table format, perhaps? Bi-Directional [ J2-3 ] gave me fits until I studied the schematic, as the docs currently state it is an output pin.