Tecwyn Twmffat

Excellent build!How do you get it to move smoothly? I've built a similar thing to track insects, https://hackaday.io/project/161581-wasp-and-asian...but the Python Adafruit Raspberry Pi library seems to shift the servos by one whole degree at a time which makes it really rough. Did you have to tweak the arduino library at all and if so, what did you do?Also, what do you think is the actual resolution of these type of servos, in degrees? .... Thanks!

Good comment! There are two reasons for using the LoRa module :1. Very long range (up to 200km) and 2. Very low power consumption, especially when compared to WIFI modules.Like you mentioned, antenna is important and getting it up high may be necessary to get line of sight.Using an amplifier is (I believe) illegal on my island and output power is limited. If I was somewhere where I could amplify signal I'd use a Qorvo QPL9065 low noise amp and appropriate band pass filters to add 20 dB to signal strength.

WIFI wont give the range needed. Lora has up to 200 km with true line of sight.

WIFI wont give the range needed. Lora has up to 200 km with true line of sight.

Thanks - I'm hoping to win a mug!

WIFI wont give the range needed. Lora has up to 200 km with true line of sight.

Thanks for reply. I can see that the bot itself has some issues, but proof of concept for using the tags is the main thing I'm interested in. I'm not sure what 95% means as I don't know the spacing of the tags. What do you think the accuracy is in mm? Maybe +- 5 mm?

Nice - what kind of accuracy do you get?

The results are very good - everything on it works fine. I'm not quite sure what the hardest part is yet - I'm trying to get the torque balanced on the drive wheels at the moment.Distinguishing weeds would be done by another separate 'off the shelf' module which would then provide coordinates of a grid to the main controller, so not really too complicated, hopefully.It's true that intricate projects get side-lined here - a few reasons: This site is aimed primarily at young people who need simple projects to learn on and intricate projects are too intimidating also the site moderators wont understand the project so will default to the garbage bin.

Yes I reckon it has the intelligence of a bacteria.

Thanks ! Just waiting for a motor upgrade to arrive tomorrow to test it all out in real life.

You can use my code!

I'm just doing it right now:https://www.instructables.com/id/WEEDINATOR-Part-4-Differential-Steering-Geometry-C/

Wow thanks! I'll try and save a bottle of sloe gin for you, current batch is 3 gallons so it should not be too difficult.

Thank you!

These guns would be perfect for the crew of my ship. Real guns would be inappropriate as they're always getting extraordinary drunk and would just end up hurting each other by mistake. I'd have to hide the actual nails though.

It's an autonomous tractor that specializes in weeding by using an onboard CNC machine.

Do mean welding aluminium or welding in general? There's no big secret to welding aluminium :)

I can weld aluminium ok - it's just that it's very expensive.

Thanks Sam - comments are appreciated! Please could you elaborate on why you think it's over built? I am trying to remove as much bulk as possible with the plasma cutter.

Thanks for your comment, Mark. Next instructable will be about building the chassis, which was finished today. Should get it published in the next week or so. After that it would be the CNC build but there might be a bit of a delay whilst I try and get some sponsorship from my suppliers.I was not expecting to get the whole machine finished until 2019, but progress has been faster than expected so there will probably be a working prototype in the Spring 2018 for 'Proof of Concept'.

Yes no problem - pleased to help.

Thanks for the tips. I'll need to repeat my tests with the base station 100 metres away from the rover and see if there is any extra error. Obviously, if it was 10,000 metres away the environmental conditions such as cloud and humidity would be different so there would then be more error.Radar sounds like a good idea and I did look into it briefly. I don't think it's so easy to get an 'Out of the Box' solution as with GPS / GNSS. I'm sure that if WW3 breaks out then all the satellites will go offline, but until then I think I'll carry on using them!

Very Cool!

Yes .... You are absolutely ..... I'm secretly planning to colonise Mars and build a large 5 star hotel for future travellers. There will be a 'Low Gravity' golf course as well.

I think this is what the RTK (Real Time Kinetics) does in the Ublox MCU.

If the Weedinator is placed in a field and there is no history in the database it will have no idea which way it is pointing without a compass and would have to travel forwards in an arbitrary direction before it got a heading. Mind you, that distance would probably only have to be about 500 mm or less so it's no big deal.

That is very true. The GPS is only accurate to 40 mm in the system and yes it does have the groundstation, base station whatever you want to call it . There are various object recognition options available and the technology is for this advancing very rapidly at the moment. Four example, check out google AIY .

Hello Hamblinm - You are very welcome to build your own Weedinator - just check out the license here: https://creativecommons.org/licenses/by-nc-sa/2.5/A 50 hp diesel engine sounds like a good idea.

Most of the work will be done by a rotating claw that moves around inside the Weedinator chassis as in animation. It wont spray any herbicide and will be able to recognise weeds through object recognition cameras. It will probably also have some kind of pest control system eg an on board water canon for pigeons. - not sure of the details yet.

Weedinator - an autonomous agricultural electric tractor that can be used on small farms to cultivate, till, plant and weed seed beds. It will be able to travel up and down 56 inch wide beds, several times a day if necessary, performing a multitude of quite delicate tasks which a big tractor might struggle with. Some of the key advantages are:Less need for heavy cultivation such as ploughing which destroys soil structure. Preservation of soil health by keeping essential natural micro-organisms and nutrients near the top of the seed bed rather than burying them. No fumes or pollution especially in glasshouses or polytunnels. Will help small farms compete financially with big industrial producers.Will the Weedinator destroy jobs or will it encourage lots more people to set ...

Weedinator - an autonomous agricultural electric tractor that can be used on small farms to cultivate, till, plant and weed seed beds. It will be able to travel up and down 56 inch wide beds, several times a day if necessary, performing a multitude of quite delicate tasks which a big tractor might struggle with. Some of the key advantages are:Less need for heavy cultivation such as ploughing which destroys soil structure. Preservation of soil health by keeping essential natural micro-organisms and nutrients near the top of the seed bed rather than burying them. No fumes or pollution especially in glasshouses or polytunnels. Will help small farms compete financially with big industrial producers.Will the Weedinator destroy jobs or will it encourage lots more people to set up small farms and help protect the environment? (Let me know what you think).

Very nice instructable! Watch out for the UV light from the welder as it contains just the right wavelengths to give you skin cancer - Never weld in shorts or T shirt or both!

Very nice!

Thanks skrubol - that's a really good tip. I found some 8Nm motors here: http://www.electrocraft.com/products/bldc/RP34/Not sure what the price would be yet.

Thank you!

Normally a tractor will have rigid back axles and a front axle that swivels in the XY plane. I could have copied the normal tractor design, but this solution saves a lot of weight and enable all four drive units to have the same design so easier to build and maintain.

I'll research that - thanks!

yes please - that would be really useful.

Ah yes ..... so how big will it be and how fast will it travel?

Thanks - hopefully it will indeed be of benefit.

The choice of suitable motors is an ongoing conundrum! I chose stepper motors, not specifically for their fine control, but more for their large torque characteristics at low speed. Imagine how much less torque a cheap servo motor would produce? The torque is required to navigate rough ground and drive over obstacles such as mole hills etc.The stepper motor on the main drive is supposed to be able to deliver a massive 12Nm, which = 1200Nm on the output of the 100:1 gearbox. It's not doing anything near that yet so there's a bit of tweaking to be done with alternative electronic controllers and higher voltages. At the moment it's just about ok and should manage most mole hills at low speed.

Is that 6" x 6" ? We work in (mostly) metrick on my ship :)

Thanks Neil - I tried to make it a bit more relevant to the instructables readership - I'm sure nobody will actually build this machine (except Elon Musk of course!)

I don't mind if Elon Musk steals the design as long as he pays for it! Not suitable for Mars anyway as they have about 1/3 our gravity.

☠☠☠ Welcome back! ... Not that I've been here much myself .... But now you're here again, that may change! ☠☠☠

Obviously safety is an issue here, but what happened with your math grades? Could I use my annual tax return as rocket fuel as an effective tax avoidance scheme?

I'm not really remaking the signal - there's no ADCs and the Arduino is just used for control and monitoring. The signal is filtered and amplified - that's it! The filtering is to stop interference with other signals such as TV and radio. The amplifier to account for losses in the cables and the filter.Have a go at building it - you don't have to have the Arduino, VGA and RSSI if you just use the LNA circuit and the filter. The VGA does not work without the LNA before it. The filter is then probably the hardest bit to do - you need a PCB and the ceramic filter - I have some spare PCBs if you need one.

Yes - I started it in January, so that's nearly 6 months I've taken to get this far. Honestly ..... I promise you I have absolutely no previous radio experience - I've not ever build a crystal radio or designed RF PCBs - not in this lifetime anyway. I started by learning to use an SDR in January. Steep learning curve!

6 months to learn RF and build the device. Yes, the Qorvo board is expensive and I think with all the mistakes I've made it has cost me nearly $1,000 dollars. Fortunately, it won the Hackaday 'Design your Concept' semi finals prize which was big cash injection for the project :)I think the final Arduino shield will retail at something like $120 sometime next year at my current rate of progress.

I got this project to work: https://hackaday.io/project/20500-cell-phone-signal-repeater-booster-femtocell

The engraving machine actually came with an Arduino and a 3 axis control board all ready set up to go but it could only be operated through the serial port of my computer. I did use it to automatically engrave a nice pretty shape but soon got bored with it and converted it to manual, as above.The main reason for going to manual is that I only ever want to make one or two PCBs and so to go through all the hassle of programming it would be incredibly time consuming compared to the benefit. I could have used the manual controls on the computer I suppose, but they were limited to 3 axis and were not very nice to use. With the sliders I can just buzz across to the component, pick it up and then place it to about 1/10 mm by gently nudging the fine tuning slider back or forwards.